The cps is a composite plastic standoff designed for increased concrete surface area. No. Cps6: 5-5/16" L. X 5-5/16" W. X 1" H., use 4-10d fasteners in post and 5/8" Anchor bolt. No. Cps4: 3-1/4" L. X 3-1/4" W. X 1" H., use 4-10d fasteners in post and 5/8" Anchor bolt. No. Cps5: 4-1/8" L. X 4-1/8" W. X 1" H., use 4-10d fasteners in post and 5/8" Anchor bolt.