Hole-In-One Cover adjusts to fit any diameter hole from 3" to 12". Hole-in-One Cover saves time and moneyReusable portablePrevents accidents and injuriesNo sawing, pre-drilling or bolting into concrete necessaryNo surface damage to surrounding concreteSafety orange color for easy recognitionAssembly hardware includedTwo screwdrivers are only tools necessary for assemblyAssembles & removes in secondsBeveled edges to prevent tripping hazardsOSHA Hole-in-One Cover Standards can be found here.