Mersen's Surge-Trap® Type 1 SPD is a  fail-safe and economical solution for applications that require a NEMA-style SPD. It is UL 1449 3rd edition approved and offers a wide range of voltage configurations to meet all needs in its class.  The Surge-Trap® Type 1 SPD features Mersen's patented TPMOV® technology eliminating the need for additional overcurrent  protection, thus providing substantial cost savings.