UNLIKE A REED SWITCH THAT INDISCRIMINATELY RESPONDS TO ANY MAGNETIC FIELD and within a global activation zone, the MAGNASPHERE switch will only respond to a magnet within a restricted zone. If a defeat magnet tries to defeat the switch, it will actually pull the MAGNASPHERE ball off the center electrode thereby opening the switch and triggering and alarm. It is this distinctive characteristic that makes the MAGNASPHERE high security switch the best choice for security sensors. >>