4-digit keyless combination locking bolt for gates, sheds, fences and outbuildings. Set your own code from 10,000 possible combinations and there's no key to lose, carry or copy. It's a simple mechanical rotary-dial lock - there are no batteries, electronics or keypad involved, so there's nothing to fail or need replacing in cold or wet weather, just four dials and a solid steel bolt doing the work. The lock body is zinc alloy with a rust-resistant coating, giving reliable weather resistance for outdoor use year-round, while the four dials are chrome plated and pick-resistant, turning smoothly while resisting casual manipulation. The sliding bolt itself is 10mm (0.39in) solid steel rather than the body alloy, which puts genuine mechanical strength at the point that actually secures the door or gate. Fitting uses the supplied one-way security screws, which turn in one direction only once driven home, so once installed the fixings can't be removed from the outside with an ordinary screwdriver. At 123 x 48 x 40mm (4.84 x 1.89 x 1.57in) overall, the unit is compact enough to mount on a standard gate rail, shed door frame or cupboard stile without looking oversized.