250 MCM-4 AWG Split Bolt ConnectorCopper Split Bolt, Conductor Range for Equal Main & Tap 250 4, Tin Plated, UL, CSA Manufactured from high strength copper alloy. Provides maximum conductivity and high breakage resistance, Electro tin plated bolt, nut, spacer and pressure bar. Provides low contact resistance, Suitable for use in circuits rated 35KV or less; proper high voltage spacing and insulation techniques must be used,For use with copper conductor types: Solid, Compact,