Snapbloc® offers a modular design that is easy to assemble. Lexan® insulating base. Lexan® is a registered trademark of the General Electric Company. Easy to assemble. LDAU, LDBU are tested to UL 1953. LDA,LDB are tested to UL 1059 90° C 600 Volts and are CSA Certified. UL Assigned Short Circuit Current Rating (SCCR) 10,000 Amps. Manufactured from high strength aluminum.