The Littelfuse Industrial TMOV34S® series thermally protected varistor represents a new development in circuit protection.It consists of a 34mm square format varistor element ( MOV) with an integral thermally activated element designed to open in the event of overheating due to abnormal over-voltage, limited current conditions. Certain TMOV34S devices are offered with a "monitor" lead which may be connected to signalling circuity to indicate if the MOV has been disconnected from the circuit. TMOV34S Series devices offer quick thermal response due to the close proximity of the integrated thermal element to the MOV body. The integrated configuration also offers lower inductance than most discreet solutions resulting in improved clamping performance to fast over voltage transients. UL1449 3rd Edition approval of TMOV34S Series is currently pending related to the integrated thermal element of this series. Contact your Littelfuse product representative to discuss alternatives and for additional information.