[Dimension] - Cable Length: 48.5cm/19.1"; Overall Size: 106 x 37.3 x 9.7mm, 106 x 15 x 15mm
[Material]: Magnetic switch alarm has zinc alloy casing for better oxidation resistance
[NO/NC] - NC means normally closed: when the magnet is together, the circuit is conductive ; when the magnet separates, the circuit is non-conductive . NO means normally open: when the magnet separates, the circuit is conducting
[Applications] - The rolling door is designed for use with door and window alarm systems, such as garages, industrial warehouses and shops, etc.