Edwards Signaling 2757-L 2757 Series Magnetic Contact, Alum, 50V op voltage, 0.5A, 25VA/W, SPDT, surface mount triple-biased, 3', 0.375" gap.

2757 Series Magnetic Contact, anodized Alum, 50V op voltage, 0.5A, 25VA/W, SPDT, surface mount triple-biased, high-security concealed magnetic contacts 3 ft vinyl jacketed cable, 0.375 in gap. The 2700 Series High Security magnetic contacts with triple-biased reeds are highly resistant to defeat by external magnets. Specifically designed for high-security applications in prisons, military installations, government facilities, and commercial operations, the 2757/2767 series magnetic contacts are virtually impossible to defeat. Total encapsulation coupled with recess mounting prevents access to the switch and to cabling, and prevents tampering with an external magnet. The contacts are factory-calibrated for operation in steel and are not subject to sticking or freezing on seldom-used doors.