The Presomatic deadbolt can replace your exisiting deadbolt or be installed on a new door installation. Completely mechanical, you''ll never have to worry about batteries failing on you, leaving you locked out of your house again. When the Presomatic lock is installed into your door, it becomes an integral part of the installation, making it even more difficult to penetrate the door and nearly impossible to remove the lock itself unlike other lock sets that are mounted on the surface of the door only.Features:• Deadbolt Lock - Locks manually by pressing the lock button on the interior or the reset button on the exterior.• Unlocks automatically when the correct combination is entered.• Nightlatch Feature - allows the user to lock out other users who know the combination.• Hardened steel solid free turning bolt, resists being cut.• Solid cast body fits ''inside'' the door for strength & appearance. Flush mounting means the lock cannot be spun or knocked off the door, like surface mount locks can be.• Large buttons are easy for use by all ages, those with long nails, and some with physical challenges - No knobs to turn!• Constructed of solid weather resistant materials for years of lasting performance.• Completely serviceable and rebuildable.• Marine grade finish lasts for years without tarnishing or fading.• Great for out-buildings and remote buildings• Weather resistant, not affected by low or high temperaturesWarranty: All Presomatic Keyless Door Locks are protected by a 1-year warranty against manufacturer defects.Manufacturer Notes:• Custom combinations may not contain the same numbers in a row, ie: 1223 will not work due to the two 2''s being "next" to one another, 1232 however will.• Lock requires 4-1/4" from the edge of the door, measure to ensure that door accents and trim pieces will not interfere.