Cobra Wire 10-Gauge Tinned Copper Primary Wire Black cover is made of a unique flame retardant polyvinyl chloride compound (VW-1) that is moisture, abrasion, acid, diesel fuel and oil resistant High Strand Count for Excellent Flexibility Class K Fully Tinned Copper Stranding, 100 Feet Spool RoHS compliant Meets UL, ABYC and USGC Standards