The Builders Edge Super Jumbo Electrical Mounting Block has UL listed 18 Cu. In. outlet box . Mounting blocks are durable, maintenance-free, U. V. stabilized and constructed with color molded-through so they wont 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 . Proudly made in the USA! .