sohomill electronic door knob with backup mechanical key (spring latch lock; not deadbolt; not phone connected), single front keypad yl 99 b sohomill warning!!! this is not a dead-bolt: when you press a valid code, you need to turn the keypad knob to unlock within 3-sec while beeping! this is also a security feature "auto-lock" to prevent from "forgot-to-lock." this is a spring latch lock. the latch does not have motor and does not move itself. therefore, it lasts longer than deadbolt. again, you will need to turn the keypad knob to unlock. install this door knob yourself! everything included: you just need a screwdriver, no professionals needed (saving on contractor costs)! don't worry about losing, forgetting, or making extra keys time and time again. fits in standard door knob installation hole. you're free to add, change, or delete user codes. this lock works for exterior, interior, side, or garage entry doors. for family, each member can have their own user code to access. coming home late at night? no problem. the keypad is lit up by led when pressed, so you can see it in the dark. if relatives are visiting, set a temporary code for their stay. no spare keys needed. going for a jog or a ride, no more carrying a bulky key chain or worrying about losing your keys along the way. press your code and you are home. pet lover: this lock will allow you to give your neighbor or pet sitter an user code of their own while you are away. when you return, simply delete the code from the lock. for rental or vacation home owner, this will reduce your costs in replacing locks and making extra keys. install this lock on your rental property and save yourself the hassle, too. when your renter moves out, simply delete or change the code. please note: while this door knob is designed for operational temperature from 6-degree f to 102-degree f in outdoor and indoor applications, it is recommended to be under a porch or some kind of overhead cover, and it should not directly to be exposed to heavy rains or accumulated snow or melting ice. please refer to photos in the listing and to our web site faqs.