YB-500A (LED) is an Narrow panel all-metal construction electric bolt .with Autolock Time Delay function. The security type of this Bolt is Locked when energizedIn order to meet with special security standard . The bolt is made of 304 stainless steel solid bar by CNC lathe and with burglary resistant design .Able to worked in the temperature of 60 ℃ or -40 ℃