Only the klm is cca, the knuflex is pure copper. Ive seen the klm, it's not bad for a smaller type setup, but on any higher current setup, definitely go with the flex or get the kicker kit. FYI, I've owned the kicker 0guage kit for 2 years now and I love it, I also have 40 feet of Knu 0 guage flex on the way right now. Try to stay away from the cheaper kits if you can, My first 0guage kit was a voodoo, and when the kicker came in, I compared the 2, and the kicker definitely has more strands/thicker wire.