I'm not going to lie, this isn't the best kit out there. In fact, far from. From what I can gather, this kit is cheap because it is using CCA (copper clad aluminium) wiring, and not OFC (oxygen-free copper). As such, the wire in this kit will NOT handle the same amount of electrical load as a 4 AWG OFC cable.That being said, for having CCA wire, this kit is definitely a steal at it's current price (~20 when I bought it vs ~60 for OFC). It has everything you'll need to get started, and it's all good enough to be serviceable. The selling point here, though, is the gauge of the wire. Most CCA kits are very much undersized, and with a larger insulator in order to give off the appearance of true 4 gauge. But the wire in this kit appears to be actual 4 gauge (compared to a 4 gauge battery cable I had laying around). Because of this, there should be no doubt of what this kit can power.As a general rule, CCA should always be treated as being as capable as its 2 gauge lower OFC counterpart. This means that this particular 4 gauge CCA cable is more along the lines of a 6 gauge OFC cable. This means it should be able to power around 600 watts RMS without too much trouble. Going beyond this, however, may cause the CCA cable to overheat and begin to melt (please see 6/17/18 update below).For me, I have it powering around 376 watts RMS across two amps (one for two 12" Aplines and a smaller one for my front door speakers). The wire does not get warm to the touch, even after running my system up quite loud over a decent period of time (~1 to 2 hours).Another thing to keep in mind is that CCA has a tendency to corrode MUCH quicker than OFC. In fact, I've seen some of my CCA wire that I used for other projects (not the wire in this particular kit) corrode in less than a year. As such, I recommend treating connections with dielectric grease, which will help to protect the connections from corrosion. Do this, at least under the hood where it is more prone to outside elements, and you should be fine. Just keep an eye on it.Another thing to keep in mind is that the fuse holder in this kit is NOT water proof. So do not put it in an area that is likely to get wet, and ensure that you use dielectric grease on the connections to the fuse.Overall, this kit is too good to pass up, so long as you understand its limitations and that you get what you pay for. This is NOT a premium kit. I realize there is a bad stigma against CCA, but, if you stay within the limitations of the CCA wire, it's really hard to go wrong.AFTERTHOUGHT: The speaker wire included with this kit is pretty junky looking, in my opinion. I used it myself, but only because I know I'm not going to put more than 38 watts RMS through them (probably less than that even). Fine for a small external amp for door speakers. Not so much recommended for subwoofers capable of 100+ watts RMS.UPDATE 6/17/18:So, I went a little bit overboard recently, and wound up adding two more 12" subwoofers, in addition to the two Alpines I already had, for a total of four 12s. In order to power all of this sufficiently, I decided to get a decent budget amp from Rockville (Rockville dB45 3200 Watt/1600w RMS 4 Channel Amplifier Car Stereo Amp, Loud!!). Running them bridged should push, at most, 800 RMS, which exceeds what I recommended above.To add a little more salt, I also upgraded the front amplifier for my doors to a budget 2-channel that I picked up from WalMart (Dual XPR82D). It has a CEA rating of 80 watts RMS, per channel. So, if I understand correctly, this means it is pushing up to 160 RMS between my two door speakers (I have the gain all the way up, with no distortion).After doing the math, it would appear that I am running up to 960 RMS, give or take depending on listening volume. Probably a smidge less, but definitely more than the 600 I recommended earlier.The point of this update is to share that I've yet to feel my power wire so much as get warm, and I haven't changed it out, or even added to it. Does this mean that I changed my recommendation? Well, no. After all, I am running a secondary battery specifically made for car audio. I'm no engineer, but I'm guessing that this battery could be helping to keep the load off the main wire during peak power usage from my amps, considering it has a lower resistance and is closer to my amps.Take this update with a grain of salt. I just wanted to share my positive experience thus far. Completely on you if you choose to take the same risk and start some kind of fire by accident. I will update if my experience changes.ANOTHER UPDATE 3/25/19:I have since changed my setup a little bit. Life circumstances changed and, as a result, the space I need in my vehicle also changed. Due to this change, I went down to a single amp, and a single 12" Alpine. Still rocking the Rockville, but it's now powering my entire sound system (two 6x9 doors and the 12).The only thing that hasn't seen a major change in nearly a year is the power wire. It is still holding up fantastically. It has yet to get warm, or cause any noticeable issues with my setup. I still check it once in awhile to ensure it hasn't corroded. Luckily, the dielectric grease trick appears to be working, as I've yet to see any signs of corrosion.I'll update this review again if anything negative happens with the power wire down the line. If that update never comes, then it's safe to assume that the wire remained in good condition for as long as I needed it.