Simplex 7104 SC Lock

Simplex locks like this have been used as access controls on government programs for years, with good reason. They don't offer a huge number of combinations, but criminals never try that approach. They're simple to program, require no power or maintenance, very reliable, and quick to use. You can open one in about 5 seconds when blindfolded. If you have a door or gate that needs to stay locked against casual criminals but is very user-friendly and quick to use, you can't go wrong with this one. Every lockset needs careful alignment to prevent binding and this one is no different, but you'll soon love its convenience. Those who've never used one of these may not be aware that a programmed step can require multiple buttons pressed simultaneously. Each button can only be pressed once in a sequence. The factory default combination is (24)-3 which means to press 2 and 4 simultaneously, then 3.

no batteries required, easy to install, easy to program my code, I now have this lock on every exterior door and on my fence gates. The description was not clear, and I ordered two of these with dead bolts (I wanted an auto lock) -- my mistake, so I set them aside in case I ever have need of a deadbolt lock. Sure is nice to be able to enter without having to lug around a set of keys, or wonder if the batteries will go tango uniform and leave me locked out.

These do work correctly if it's installed correctly. If you jam the bolt because of shotty work and shortcuts it won't work right. Make sure the door is aligned and the bolt can move freely. If it rubs in the jamb you need to correct that as you would with every other lock. Good stuff, I'd recommend :-)