[EASY TO PROGRAM AND CHILD-PROOF]: A truly convenient alternative to traditional keys. Manage 1 administrator code and up to 100 passcodes using a single keypad. Perfect door knob with lock for room rentals, house-keeping, offices, storage rooms, bedrooms, dormitory management and more, also manage your children's access to a specific room such as computer room (gaming), garage workshop or storage room, etc. [FASHION DESIGN FOR YOUR HOME]:Design rotary knob has a texture and design optimized for long term grip comfort; The main structure, made by tested Zinc Alloy materials, delivers the robust and sturdy construction, enabling it to handle intensive day-to-day use; operates on 4 AAA batteries(not included) that will last up 1 year. [MULTI-FUNCTION]: this door knob automatically locks 5 seconds after being opened. However, when there is a need to leave the door unlocked for a while, simply activate the Passage Mode; Turn on Silent Mode if you don't want others to hear any