Review on Pyle 50ft 12 Gauge Speaker Wire - High-Quality Copper Cable on Spool for Seamless Audio Stereo Connection to Amplifier, Surround Sound System, TV Home Theater, and Car Stereo - PSC1250 by Justin Smith

Others say it's not copper but it might be random like mine. Looking at the manufacturer's cut, it initially looked like aluminum in the middle, but I think that's just to prevent wear when cutting. I cut off a couple of inches and found something similar to weaving copper threads. Unless every strand of aluminum is sheathed in copper, it is actually copper wire. They seem to produce a richer sound than the 16 gauge cable I used to run to my front speakers in my 7.1. So far I don't see anything wrong with the cable, especially when connected to Ocelot's banana plugs. YMMV