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;