Materials face and base are nylon, strap is 0.05" thick steel, zinc plated, auto ground clip is bronze wire
Line contacts are 0.037" triple-wipe brass, terminal screws are number 8-32 steel, ground screw is number 8-32 steel (green)
Screw terminal guards are PVC
Listed to UL 498, UL verified to Federal Spec. WC-596G, CSA Certified to C22.2, no. 42. Flammability meets UL 94 requirements; V2.temperature rating: -4 to 158 degrees F. Dielectric voltage: withstands 2000 volts per UL 498.