GSM Access Control is GSM remote control unit for door & gates openning. To open the door you can type your unique 4 digits PIN access code into the CodeLock keypad or dial the mobile number of the W-LOCK unit free of charge (Caller ID). When the correct PIN access code or CLIP is recognized the W-LOCK unit opens the gates/door. Changing the PIN access codes, setting the phone numbers and other parameters can be programmed remotely by sending text (SMS) to the unit. Typical use of the W-LOCK: rental apartments, holiday houses, restricted access areas, storages, laboratories, etc.