The Builders Edge 4" Hooded Dryer Vent comes complete with 8" aluminum tube (4" diameter); Net free area: 12 sq in. Mounting blocks are durable, maintenance-free, U.V. stabilized and constructed with color molded-through so they won't scratch, flake, or fade. Our patented Snap-On Trim Ring makes installation easy. Available in 24 colors to match your siding manufacturer and a Paintable option to easily match your home. Limited lifetime warranty. Proudly made in the USA!.