The Ilsco CTL-4/0 SureCrimp Copper Compression Sleeve is designed for reliable electrical connections. This tin-plated copper sleeve is built for long-lasting performance and is UL and CSA recognized, ensuring it meets stringent industry standards for safety and quality.This is a SureCrimp copper compression sleeve designed for conductors sized 4/0. It features a long barrel and is tin-plated for enhanced conductivity and corrosion resistance. The sleeve is UL and CSA recognized. The provided supplier catalog data suggests a potential cross-reference to GL0400... / GLX420400, which is described as a 400A general-purpose current device according to UL98, with a rated insulation voltage of 1,000V and a rated impulse withstand of 12kV. Mechanical life varies by amperage rating.