The 1-piece design can be used after siding installation to mount all types of accessories. Compatible with Double 4" or Double 5" siding profiles. Manufactured with ultraviolet-stabilized color, minimizing the effects of exposure to the elements. Rich textured appearance. Surface dimensions: 6-3/4" x 6-3/4". Projection: 3/4". Knockouts: Round 1" diameter; rectangle 2-3/8" x 3-3/4". Limited lifetime warranty.