Invincible Marine Heavy-Duty Clamp-On Oarlock Horns, 2-Pack Made using the highest quality components Performance and quality tested The most trusted name in marine accessories and equipment Fasten securely to the oar with one adjustable bolt and no drilling required These are clamp-on oarlocks have a 1-5/16-inch to 2-1/8 diameter for oar shafts and a -inch shank Packaged as a 2-pack Comes with a 1-year warranty