Nascom's N505AS Is A Short, 2" Block Switch, Designed For Man Doors. ItCombines The Installers' Choice Of Contact Configuration With An N35 NdfebMagnet For Maximum Gap Performance.The Closed Loop Version Of The N505AS Prevents False Alarms Caused ByWarping Or Shifting Of Doors, And Features Our Unique NO DEAD SPOT? Technology.FEATURESNO DEAD SPOT? TECHNOLOGY24" ARMORED CABLE LEAD PROTECTIONEXTRA WIDE GAP - N35 NdFeB RARE EARTH MAGNET36" 22AWG WIRE LEADSLISTED TO UL634 STANDARDEXTRUDED ANODIZED (TYPE II) ALUMINUM