Elemake Keyless Deadbolt Lock - Keyless Entry Door Lock Keypad Door Knob Exterior, Digital Code Security Door Lock with Keys Mechanical Lock Stainless Steel 304, HIGHER CONVENIENCE & SECURITY -- It can be opened with both the pass code or the key; Wear-free keypad material, no clues left for thieves (Initial password: 159260, not 123678 as listed in the user manual!), 100% MECHANICAL STAINLESS STEEL 304 -- No risk of low battery, lock easily by turning the knob left or using key to lock it, open passcode or key. This lock is very difficult to pry open and deadbolt is extra sturdy. Does not lock automatically (This can be a pro or con depending on your needs), Suitable for standard prepared doors, borehole can not less than 1-15/16"", maximum borehole diameter 2-1/8"" (Suitable for wood or metal door thickness of 35-50mm/1.38-1.96inch), works with both left/right handed and inward/outward opening doors, DESIGN FOR DIY INSTALLATION -- Combination can be 4-8 digits (no repeats) . Please refer to the installation video. Please note that the combination code can be used in any order, TRUSTED QUALITY AND 100% SATISFACTION SERVICE -- Elemake provides 10 years factory warranty, If you are not satisfied with the product, please contact us to refund or replace the product, ,