Check the listing for details. 5 x Wired Door Contact Sensor SHOP NC Surface Mount Magnetic Reed Switch. Condition: New. Listed at 13.45 USD. Description:[Specification] - Type: Normally Closed (NC); Max Sensing Distance: 10mm; Cable Length: 30cm/ 11.8"; Total Size: 29x15.35mm/ 11.42" x 6.04" (L*W); Max. Current: 0.5A; Max. Voltage: 100V; Max. Power: 10W[Installation Dimension] - Installation Hole Size: 8x4mm; Installation Hole Distance: 15mm[Durable Material] - The magnetic switch alarm is with durable PVC housing for better rust resistance[Normally Open] - NC means Normally Closed: When the magnet together, the circuit is conductive( light on ); when the magnet separates, the circuit is not conductive ( light off ).[Applications] - The Wired Door Sensor is designed for use with window and door alarm systems, such as the garage, industrial warehouse, and shops, etc.