NI-610-L-A sturdiness electric bolt lock is a High security lock suitable for framed glass doors, wooden doors, metal doors, fire doors. Unique solenoid valve control, more stable, low failure rate. Lock body are made of High-strength aluminum alloy, all solid lock withstand 3000 pounds linear positive impact.https://www.chinanordson.com/sturdiness-electric-drop%E2%80%82bolts/electric-bolt-for-narrow-door.html