Carlisle Brass Thumb Turn with Release 50mm (Dia) Polished Brass is manufactured from solid brass. It is used to provide security for interior and exterior doors of the household. The product also prevents prying eyes seeing into a room. It aids in the prevention of draughts or the ingress of dust as well as insects. It also protects a lock cylinder from being drilled out. The thumb turn lock has concealed screw fixing on each side of the keyhole for secure fitting. The oval shaped thumb turn with coin release is ideal for use with a bathroom lock. Corrosion resistant. Concealed fix for privacy. Scratch resistant.