This knob set is constructed of zinc alloy (cast zamak) and comes in a polished chrome plated finish. It is designed for use with a concealed latching mechanism, and it assembles easily with a security fastener. This knob set has a 1-5/8 inch outside diameter, and it features a flat, slotted emergency-access knob on the exterior. Knob sets like these are used to replace broken and missing lever and knob sets of concealed latches. For use as a privacy lock in toilet partition stalls manufactured by flush metal. Note: assembly will be permanent upon first unification of both parts. Attempting to separate the inside and outside knobs Once joined may damage the internal push nut fastener.