Blast round ceiling box is simply set in place 4.25-inch/108mm above bottom of ceiling/tile and sandwich trim between box and fixture base. Cutout sizes for Blast ceiling trims, always center ceiling box in trim cutout. These handy trims sandwich between any Blast Powercore fixture and ceiling box, turning Blast into powerful recessed downlight or wall washer. For use with Philips color kinetics color blast powercore, Philips color kinetics burst powercore and Philips color kinetics compact burst powercore.