Globe Electric 9212701 Accessory, Aluminum IDEAL FOR ATTICS: ideal for attics, Globe's insulation box is used for installation of non-IC rated recessed lighting kits in insulated ceilings UNIVERSAL SIZING: can be used with Globe Electric's 3", 4" or 5" recessed lighting kits. Actual hole sizes: 3.25", 3.88", 4.25" and 4.5" PATENTED BRACKETS: features patented brackets for one-handed installation EASY INSTALLATION: comes with four adjustable hanger bars and two knockouts for easy wiring - should be used with a standard ceiling tile thickness of 0.625" or more INSPECTOR APPROVED: inspector approved for non-IC rated lighting kits. Not applicable with MR16 Shape recessed fixtures