Review on GearIT 14/2 Speaker Wire (250Ft) - High-Quality 14AWG Gauge For Outdoor Use - Oxygen-Free Copper - CL3 CL2 Rated - 2 Conductors - Black by Antonio Gonzalez

This is 100% copper. Not that combo aluminum junk. Insulation is good. I had to pull this through a tight 1/2 in PVC pipe and insulation held up well. The copper strands are thin but didn't have any issues with them. Obviously I could pay alot more to get a thicker strand. I am driving a pair of Klipsche 650 Outdoor speakers. Speakers and wire produced nice clean audio - highs, mids and low frequency that I expected from a high powered Klipsche speaker and Older Yamaha Receiver that can drive high and clean power.