Universal for various door opening directions.

Multiple unlocking ways including linkage, knob, key, etc.

Automatically locks if the door is not opened within 15 seconds of being unlocked.

Auto locking after door closing, no door slamming, no noise.

Low power consumption: Only 1/5 of the power consumption of electric locks.

Long lifetime of 350,000 cycles.

Audible alerts for door unlocking and closing.