TTlock App fingerprint, card, mechanical key unlock; easy to use it whether children or older. Never worry forget tobring the key. This keyless entry door lock allows you to check the visitor records on TTlock APP, see which visitor at what time unlocked the door. Mechanical keys and emergency power supply (Type-C) can be used when the door lock is out of power. 4 pcs AA batteries(Not included) can provide 5000 openings (. 6 months). Upgraded anti-touch feature. Unlock as long as the numbers you enter contain the correct sequential code. TT Lock version combined with the Gateway provides the most convenient experience by simply your smart speaker to lock or unlock our lock. Product model:A1 Applicable door thickness: 35-50mm Lock body material: aluminum alloy Lock cylinder material: copper Applicable type: interior door Applicable environment: indoor room temperature Door opening method: fingerprint, password, card, key, APP Features:Intelligent and multifunctional Applicable to door:office door Color:Silver Material:ABS Package Contents: 1 * Electronic Lock Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.