With this Philips smart lock, the world's first deadbolt with palm recognition, enjoy the most secure and convenient unlocking experience. Or unlock with a key, PIN code, or the Philips Home Access app to make returning home stress-free. The built-in proximity sensor detects your hand reaching toward the indoor knob or lever and sends unlock signals to the lock. The deadbolt will automatically unlock as you reach toward the knob, allowing you to leave with ease and not have to physically unlock the deadbolt yourself. This feature is disabled by default.