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CURT 51120 Discovery Electric Trailer Brake Controller, Time-Delay , black

4.6 4.6 out of 5 stars 1,008 ratings

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Single
Brand CURT
Item Dimensions LxWxH 8 x 2 x 5 inches
Item Weight 9.6 ounces
Style Single

About this item

  • RELIABLE SAFETY. The Discovery electric trailer brake controller offers safe, dependable operation, increasing trailer brake pressure as you depress the vehicle brake pedal and bringing the vehicle and trailer to a smooth stop
  • EASY TO USE. This trailer brake controller features an easy-to-read, digital display to monitor brake operation. It also has a simple, reliable design with no internal moving parts and no leveling required
  • POWERFUL. The simple controls of the Discovery brake controller enable powerful brake operation, featuring a manual brake slider button, an adjustable power toggle and adjustable ramp time
  • VERSATILE. You can use this electric trailer brake controller on virtually any trailer with 1 to 4 axles (2 to 8 brakes). Compatible with low-volt, PWM, ABS, cruise control and electric over hydraulic
  • SIMPLE SETUP. This electric brake controller quickly plugs into your vehicle using a CURT vehicle-specific quick plug harness (sold separately). It comes with an adjustable mounting bracket and can be mounted at any angle
See more product details

From the manufacturer

CURT Brake Controllers and Towing Accessories

Wherever your work or play takes you

CURT offers custom trailer hitches, electrical products and a complete line of towing accessories to get you there with confidence and enjoy every mile of the journey.

CURT Electric Trailer Brake Controllers 5th Wheel

CURT Electrical Trailer Brake Controllers

Simple installation. Sophisticated safety.

CURT offers several different trailer brake controller models to provide you with a solution that fits your unique towing setup and budget. We carry time-based and inertia-based or proportional brake controllers.

All CURT trailer brake controllers are designed for easy installation. Most use our quick plug harnesses, and each comes with its own set of features and benefits.

For a helpful guide in selecting a brake controller, see below.

Key features

  • Multiple styles to fit your needs and budget
  • Fast, easy installation
  • Easily calibrated for all towing needs
  • Time-based and proportional
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Echo Mobile Spectrum TriFlex Discovery Venturer
Customer Reviews
4.3 out of 5 stars
2,465
4.3 out of 5 stars
644
4.2 out of 5 stars
838
4.6 out of 5 stars
1,008
4.3 out of 5 stars
3,411
Activation Method Tri-axis inertia Tri-axis inertia Tri-axis inertia Time-based Time-based
Number of Brakes 2 to 4 2 to 8 2 to 8 2 to 8 2 to 6
Display Smartphone app Tri-color LEDs Digital Digital LEDs
Level Adjust Auto Auto Auto Auto Auto

Inertia-based vs. time-based

Two types of brake controllers:

CURT electric brake controllers fall into one of two categories: inertia-based or time-based. These refer to the method of activation used by the brake controller. Both types are safe and effective for stopping a trailer. However, depending on your needs, one may be preferred over the other.

Inertia-based

Inertia-based or proportional trailer brake controllers use an electronic mechanism, called an accelerometer, to detect the momentum of the vehicle-trailer combination while braking. The controller accentuates the trailer brakes in proportion to the momentum, allowing for a smooth, highly efficient stop.

Time-based

Time-based activation is less complex than inertia-based. When stopping, a time-based brake controller accentuates the trailer brakes based on whatever gain setting is input by the driver. Although simple in operation, time-based trailer brake controllers are effective and provide a more budget-friendly option.

How to select a trailer brake controller

Heavy-duty towing

If you are towing a heavy trailer or cargo, an inertia-based brake controller will provide superior control to make smoother stops and to put less strain on your vehicle.

Light-duty towing

If you’re towing a simple boat trailer or popup camper, a time-based trailer brake controller may be sufficient. CURT time-based controllers are easily adjustable for varying loads.

Frequent towing

If you’re planning to tow often, an inertia-based brake controller is recommended. The sophisticated operation will help prolong the life of your vehicle and trailer.

Occasional towing

If you only plan to tow a few times a year, such as for family camping trips during the summer, a time-based brake controller is an effective and budget-conscious option.

Product Description

It takes a lot of power to stop a moving trailer, especially when that trailer is hauling a heavy load. On RVs, flatbeds, livestock trailers and many other oversize haulers, manufacturers typically install trailer brakes to assist the tow vehicle in bringing such a massive amount of weight to a halt. But it takes more than a good set of brakes to make quick, efficient stops. It takes precision and the right amount of control. Discovery is a time-based brake controller, meaning it applies increasing brake pressure the longer your foot is on the brake pedal. This pressure is based on the gain setting and sensitivity adjustment set by the user. Discovery has a digital display for easy monitoring and the ability to manage up to four axles at a time. It mounts at any angle, anywhere in your vehicle and comes with an automatic power level adjustment feature to ensure you can stay better focused on your driving and spend less time worry about your trailer brakes. All CURT brake controls are designed to work with quick plugs so that they can readily plug into your vehicle's original equipment socket. They also include a mounting bracket and hardware for easy installation. A brake controller should be mounted somewhere on the dash of your vehicle, and we recommend putting it below the steering wheel, either on the right or left side of the steering column. This way the control will not block your view when driving, but it will remain accessible and visible when adjustment is needed.

Product information

Technical Details

Additional Information

Warranty & Support

Amazon.com Return Policy:Amazon.com Voluntary 30-Day Return Guarantee: You can return many items you have purchased within 30 days following delivery of the item to you. Our Voluntary 30-Day Return Guarantee does not affect your legal right of withdrawal in any way. You can find out more about the exceptions and conditions here.
For warranty information about this product, please click here [PDF ]

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CURT 51120 Discovery Electric Trailer Brake Controller, Time-Delay , black


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What's in the box

  • 1 DISCOVERY BRAKE CONTROL
  • Product guides and documents

    Looking for specific info?

    Customer reviews

    4.6 out of 5 stars
    4.6 out of 5
    1,008 global ratings

    Customers say

    Customers like the performance and ease of installation of the brake controller. For example, they mention it works great, the mounting hardware is easy to install, and the instructions are clear. That said, opinions are mixed on the quality and value.

    AI-generated from the text of customer reviews

    94 customers mention80 positive14 negative

    Customers like the performance of the electronic sensor. For example, they say it works great on their triple axle trailer, it's easy to install, and has a good price.

    "Very easy to install. Works well. Descent price." Read more

    "Got this for my Ram 1500 to tow our trailer and it works great! Definitely a must buy" Read more

    "...Simple and does the job." Read more

    "showed up quick with all parts, works flawlessly.would buy again" Read more

    58 customers mention55 positive3 negative

    Customers find the installation process of the electronic sensor to be easy. They mention that the mounting hardware is easy to install, and the instructions on how to install and program the sensor are easy to follow. Some say that the sensor is plug and play and works flawlessly.

    "Very easy to install. Works well. Descent price." Read more

    "Works great easy to install" Read more

    "...It took me about 5 minutes to adjust it after the install. Simple and does the job." Read more

    "showed up quick with all parts, works flawlessly.would buy again" Read more

    11 customers mention11 positive0 negative

    Customers find the adjustability of the electronic sensor to be easy. They mention that it's easy to set timing and level, and adjusts to different trailers and weights. Customers also say that it adjusts well for different brake pressures. They also say it'll calibrate easily.

    "...Small size made it easy to mount in an out of the way spot. Easy adjustment; easy to use. Really like this unit." Read more

    "...Easy to set timing and level." Read more

    "...Easy to follow instructions and setup. Easy to use and adjust as needed for different trailers and weights." Read more

    "...Controller is easy to adjust with digital display and delay switch on the side. Great value for the money of you need a brake controller!" Read more

    39 customers mention27 positive12 negative

    Customers are mixed about the quality of the brake controller. Some mention it's a great product, while others say it was cheaply made and the case is flimsy.

    "Great brake controller, this is my second one, the first one shorted out after 8 years. Make sure you get the correct wiring harness for your vehicle" Read more

    "Build very well.My truck died at the same time I bought this, I had to buy another truck, it already had this on it." Read more

    "...the product did arrive damaged, the second digit on the screen does not light up properly and is unreadable, not a major problem since i adjust the..." Read more

    "Pretty good brake controller. For me I had to hold the brake and the brake slide on the unit to set the sensitivity otherwise it wouldn't work." Read more

    19 customers mention13 positive6 negative

    Customers are mixed about the value of the electronic sensor. Some mention it's great value for the money, works great, and is a good choice for a value brake controller. However, others say that it'd be better off with a different brake controller or that it is cheap and a basic unit.

    "Good choice for a value brake controller. Added this to our 2013 Town and Country mini van so we can pull our pop up camper...." Read more

    "...Great value for the money of you need a brake controller!" Read more

    "...Inexpensive but it has the two main aspects of a brake controller gain adjustment and how hard you want the brakes to be...." Read more

    "...But this curt 51120 works great for the price." Read more

    14 customers mention4 positive10 negative

    Customers are dissatisfied with the mounting of the electronic sensor. For example, they mention it came without the mounting bracket or screws. Some say the mount was outside the package and just taped together. That said, some complain about the tap screw and bushings.

    "...Only gave it three stars because the mounting screws were missing. It took me longer to find screws than it did to mount it." Read more

    "...Included was the mounting bracket and all hardware. I did have to purchase the vehicle specific wiring harness." Read more

    "Came without the mounting bracket or screws... otherwise it would have been great for what we need...." Read more

    "Install was easy and product works fine but it came without the hardware to bolt the unit to the bracket...." Read more

    IF YOU WERE MISSING HARDWARE/ SCREWS READ
    4 Stars
    IF YOU WERE MISSING HARDWARE/ SCREWS READ
    It seems I was wasn't the only customer who didn't receive the "included hardware." I mounted the controller in my 2019 new style Ram 1500 using the existing screw that was attached to the plastic panel beneath the steering wheel...no drilling necessary. The size of screw you are looking for mounting the unit to the bracket is a M4- .70x 8.....I easily found these at Ace hardware. The controller itself was very easy to install once I had the screws...took maybe 10 mins and the programming was easy. Would have been 5 stars had QC caught the screw snafu.
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    Top reviews from the United States

    Reviewed in the United States on February 25, 2024
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    Reviewed in the United States on May 7, 2018
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    Reviewed in the United States on December 31, 2023
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    Reviewed in the United States on December 20, 2023
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    Top reviews from other countries

    Adam
    5.0 out of 5 stars Brake controller
    Reviewed in Canada on December 3, 2023
    Style: SingleVerified Purchase
    Angie Neeb
    5.0 out of 5 stars Works mint!
    Reviewed in Canada on July 20, 2023
    Style: SingleVerified Purchase
    Amazon Customer
    4.0 out of 5 stars Works well.
    Reviewed in Canada on August 20, 2023
    Style: SingleVerified Purchase
    Madison Leach
    5.0 out of 5 stars Exactly what the doctor ordered
    Reviewed in Canada on January 24, 2024
    Style: SingleVerified Purchase
    Customer image
    Madison Leach
    5.0 out of 5 stars Exactly what the doctor ordered
    Reviewed in Canada on January 24, 2024
    Cruised multiple shops in town for a trailer brake controller for my truck. Almost all of them were outdated and overpriced. Snagged this one off Amazon which is cheap, easy to install, and user friendly. After watching a YouTube video I had the confidence to install it myself. Easy to adjust as well. Digital display is nice.
    Images in this review
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    Customer image
    karl Simard
    5.0 out of 5 stars Fonctionne tres bien
    Reviewed in Canada on September 15, 2023
    Style: SingleVerified Purchase