These Skene Chocks provide a smooth lead for your mooring or dock lines minimizing chafing. The tips of these chocks are designed to overlap, reducing the likelihood of the motion of the boat from causing the line to accidentally work free of the chock. Left and right skene chocks included. Accommodates lines up to 3/4?. Constructed of corrosion resistant investment cast 316 stainless steel. Installs with two #10 FH fasteners (not included).?SS Skene Chocks 4-1/2"