Keeping it simple is a good rule to follow most of the time, and it certainly applies to safety padlocks and keys, as well as lockout steps for equipment maintenance.
Master Lock Company’s patent-pending, low-profile S2151 Removable and S2153 Installed Push Button and Rotary Switch Covers provide a visual and locked deterrent for temporary shutdown situations and fit both 30.5mm and 22.5mm diameter switches.