Builder's Best 110696 Saf-T-Duct Dryer Outlet Box

• Fits all 16" centers 2" x 4" & 2" x 6" ;• 6 prescored true 4" dia knockouts in most common positions ;• 6 starburst knockouts for gas connections & venting ;• Plastic meets UL standard 94HB tests for flammability ;• Self-trimming unit 18"W x 24"H ;• White;