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 fastenersin 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.