Size: RC-33 Feature: Widely Used-This Recessed Door Contact Sensor works with any access control or burglar alarm system available. Switch Type: NO(normal open type), NO means Normally Open: when the magnet separate, the circuit is not conductive( light on ); When the magnet together, the circuit is conductive (light ooff ), NC means Normally Closed; NO means Normally Open. Specification Model: RC-33 Material: ABS Rated power: 10W Rated current: 500(mA) Rated voltage: (VDC) 100 Size(Approx.): 16.7 x 10.7mm / 0.66 x 0.42inch (H*D) Cable Length(Each): 250mm / 9.8inch Wire Type: 24AWG Mounting Type: Recessed Anti-fire ABS shield Connecting mode: NC Operating distance: more than 15mm, less than 25mm Note: the Magnetic Door Switch must be installed according to the sensing distance. It can only provide a switch signal to the transmitter. It cannot directly load the power, nor directly connect the lamp! Package Includes: 2 Sets x RC-33 Magnetic Door Window Contact Sensor 【Hassle-Free Warranty】 guarantee high quality and good service. Here with our 90-day money back risk-free purchase guarantee, Refund or Replacement for any quality problem.