[Dimension] - Cable Length: 50cm/19.7"; Overall Size: 104 x 50 x 9.5mm, 104.5 x 20 x 16mm
[Material]: Magnetic switch alarm has zinc alloy casing for better oxidation resistance
[Normally Open] - NO means normally open: when the magnet separates, the circuit is conductive ; When the magnet is attached, the circuit is non-conductive . When you order, check carefully.
[Applications] - The rolling door is designed for use with door and window alarm systems, such as garages, industrial warehouses and shops, etc.