The Master Lock No. S2151 Removable Push Button and Rotary Switch Cover prohibits access to a switch or control. The cover fits both 30.5mm and 22.5mm diameter switches and accommodates buttons up to 2in (51mm) diameter and 1-3/4in (44mm) tall. The horse-shoe shaped retrofit base allows use with raised nameplates and off-center installation to accommodate rotary switch knobs and clear bases and cover allow visibility of nameplates and labels. OVERVIEW Removable Push Button and Rotary Switch Cover Prohibits access to a switch or control Fits both 30.5mm and 22.5mm diameter switches Clear bases and cover allow visibility of nameplates and labels Horse-shoe shaped retrofit base allows use with raised nameplates and off-center installation to accommodate rotary switch knobs Accommodates buttons up to 51mm diameter and 44mm tall Includes one cover, one new install base and one retrofit base with double-faced adhesive tape