CMF-SDP Telecom CPTC Resettable Fuses Bourns CMF-SDP Telecom CPTC Resettable Fuses feature two resistance-matched PTCs in a plastic housing. These fuses operate safely under fault conditions and withstand lightning surge and AC power cross. Bourns CMF-SDP fuses offer resistance values from 5.6Ω to 100Ω and assist in meeting Telcordia GR-1089 and ITU-TK.20 / K.21 / K.45 specifications. These fuses can be used as a secondary overcurrent protection device in Customer Premise Equipment (CPE), Central Office (CO), and access equipment.