Lowell's conically shaped 8XD4 backbox is engineered to accommodate an 8" speaker in either new or existing construction. The slightly tapered, conical shape allows these backboxes to be stacked for space efficient storage and transit. The 8XD4 backboxes are seamless 22-gauge electro-galvanized steel construction with a polyurethane foam disc that meets UL flammability CAL-117. The disc is affixed to the bottom inside surface to reduce acoustic and mechanical resonance. The 8XD4 is furnished with factory installed 8-32 screw retaining clips for grille mounting.

• Includes four 1/2" - 3/4" knockouts spaced at 90 degrees.
• Does not include mounting straps as it is designed for use in suspended ceilings.