The TB-61 lock is a surface-mounted lock, with latch bolt, and single-cylinder, designed to secure rooms as an additional lock next to the main lock. It is suitable for all types of doors with a thickness from 32 to 64 mm, where it is possible to drill a 30 mm hole for installing the cylinder at a distance of 60 mm from the face of the installed plate. It is recommended for use on solid (non-glass) doors with a handle.