ZZ Marts’ Release Switches category stocks door release relay modules alongside magnetic door contact sensors (surface-mount and recessed NC/NO types) used to detect whether a door is open or closed. These pair naturally — a release switch lets someone out, while a door contact sensor confirms the door has actually closed and locked behind them — making this category a common companion purchase to our Access Control & Electronic Locks range. Our Karachi and Lahore teams can advise on which contact sensor type suits your door frame and existing alarm panel.