Surface-mounted security bolt, model crr11, made of steel with a gray finish, 86l/50 mm, with 5 keys and chain, 86 mm plate and 50 mm round cylinder, designed to reinforce security by installing on any type of door. its reversible design eliminates handedness, and internal and external operation is carried out using a security key through the cylinder. it also features a cylinder protector and anti-bumping system.