SECO-LARM SD-997B-GBQ Electric Deadbolt/Fail-Safe, Adds concealed deadbolt security to most wood or hollow metal doors with the added convenience ofelectrical operation, Fail-safe operation (unlocks if power&nbsp;is lost) Adjustable door lock delay timer(0, 2.5, 5, or 9 sec), Control wire allows release without cuttingunit's power, Magnetic switch determines door position forpositive locking Solenoid attempts to lock several times and then shuts off if door not closed properly to preventburning out, Easily connects toSECO-LARM'sElectronic Keypads Suitable for office-type applications, Shallow design for use with most metaldoor jambs, No limiting installation orientation Powered by a solenoid, Stainless steel for strength and long life, 1,000,000 operations lifetime Plastic material Tefulon Polymonochlorotrifluoethylene; Over-current protection 1.5A; Stainless steel bolt, 5/8" diameter,5/8" throw