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, it has an offset bolt with a flat tip, and it assembles easily with a push nut fastener. This knob set has a 1-3/4 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 knob sets of concealed latches. This set is used with steel doors, and it is easy to install. 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 component.