Description of RWK81: The Rockville RWK81 8 AWG (American Wire Gauge) amp kit has the following diferences over other amp kits on the market at this price point.. . 1. Our RCA cables are 100 % copper. These are top of the line RCA cables.. . 2. Better Resistance: The only thing that really matters with wires is the resistance rating. This is a measurement of conductivity and how much signal is loss per foot of wire. Since Rockville wires are made with around 3 times as much copper as any other wire at this price point, these wires had a much better resistance rating which means they will transfer more power to your amps than the other brands.. . 3. We do not cheat you on the thickness of the wire. These are standard American wire gauge thickness. This is another reason our conductivity is better than anything else at this price point. Other brands in the market place write 8 gauge, but cheat you on the thickness. We are honest about the thickness.. . 4. The Rockville amplifier installation kits feature a new soft abrasion proof insulating jacket. This rugged PVC outer jacket allows for 100% improved flexibility over standard power cables making them extremely easy to route through your vehicles interior, and it maintains exceptional resistance to grease and oil. The PVC outer jacket can with-stand an extreme temperature range of -40 to 220 degrees F.