The set includes: 4 pieces spring bolt lock with 16 pieces fixing screws. Material: High quality aluminum alloy material, thick base, rustproof and brittle, safe and reliable. Size: The overall size of the automatic door lock is about 57mm x 43.7mm, the color is black; The size of the screw is 16 x 4 mm. Features: Easy installation, choose the installation location, punch holes and tighten the screws; Built-in automatic spring, stretch and gentle, just pull, loosen and automatically spring back without hurting your hands. Wide range of applications: Widely used in various doors and windows, tool boxes, storage cabinets, etc. to improve their security. Note: The data are all measured manually. Please allow an error of 1-3cm. Due to the difference between light and display, there is a certain color difference, which depends on the actual object received