Speedi-Products EX-DBK 04 18-Inch by 24-Inch Length Dryer Box, Periscope and 2 Rectangular to Round Transitions Speedi-Exhaust Products are made in the USA Speedi-Products18-Inch by 24-Inch Dryer Outlet Box Meets UL 94HB tests Provides extra space behind the dryer Fits all 16-Inch center 2 by 4 and 2 by 6 construction