Megaflint Keyless Entry Door Lock Deadbolt Keypad Mechanical Stainless Steel (Pass Code or Key ) 100% Mechanical, No Electronic, Easy to install in about an hour！Wear-free keypad material, no clues left for thieves, higher security. Does not lock automatically (This can be a pro or con depending on your needs), Slight adjustment to door knob cutout may be needed to accommodate width of lock(Borehole can not less than 1-15/16""). For double bores standard door, this lock must install on the above bore. Size 5-1/2"" x 3-1/4"", Maximum borehole diameter 2-1/8"", Suitable for standard prepared doors, maximum borehole diameter 2-1/8"" (Suitable for wood or metal door thickness of 35-50mm/1.38-1.96inch), works both left/right handed and inward/outward opening doors., 100% Mechanical (no risk of low battery), Stainless Steel deadbolt lock is extra hard (304), you can use passcode or key to lock it, or both, very difficult to pry open.Made of stainless steel #304, enhanced anti-corrosion surface treatment , features 5-15 times higher than zinc material., Replace Any Lockset, Neatly & Easily . Combination can be 4-8 digits (no repeats) with tumblers providing over 8,000 options. Please refer to the installation video. Please be noted that the combination code can be used in any order., ,