Circa 4B1S-300 300V 5 Pin Primary Telephone Surge Protector TVSS.
4B1S-300 Surge Protector.
The Circa 4B1S-300 is an advanced, 300V solid-state UL 497 primary telecommunications 5-pin surge protection module. The 4B1S-300 module fits any industry standard 5-pin building entrance protector housing. All models employ state-of-the-art silicon breakover technology as the active overvoltage clamping elements, along with PTC (positive temperature coefficient) overcurrent circuitry which allows normal Digital telephone current to pass, but quickly blocks damaging fault currents. UL & cUL listed Primary
4B1S Series PDF