The split recessed J-Block mounting block has a patented hinge that allows for ease of installation without removal of electrical receptacles and water faucets. Manufactured with ultraviolet-stabilized color, minimizing the effects of exposure to the elements. Compatible with all siding profiles. Rich textured appearance. Surface dimensions: 5-1/4' x 7'. Flange dimensions: 5-7/8' x 7-1/2'. J-Channel internal dimension: 3/4' adjusts to 1-1/4'. Knockouts: Rectangle 2-1/4' x 3-7/8'. Limited lifetime warranty.