YB-500HD(LED)Surface Mount Intelligent Single Door Electric Bolt,High-Strength Aluminum Alloy Housing,Zinc Alloy Body,304 Stainless Steel Solid Bolt,Processed by CNC,1000kgs Holding Force,Bolt comes with anti-theft high-strength security design,Metal linkages ,works in the temperature between 60 ℃ or -40 ℃?normally,durable magnetic valve applied,special photoelectric control system, ultra-low temperature and power consumption design.LED indicates status(green for unlocking;red for locking),Comes with NO/COM contacts and re-lock time delay function,Fail safe or fail secure optional,Convenient installation,time-saving,safe,sturdy,recommended model for any project