Brady patented No Hole lockout device is easy to install using patented thumbscrew design – no screwdrivers needed! Easy to install simply tighten lockout securely onto switch tongue, pull cover over thumbscrew and lock cover to prevent clamp from being loosened Fits wider and thicker switch tongues; 16mm wide x 11mm thick. AS/NZS 4836:2011; Work Health and Safety Regulations 2011.