Rowboat oarlock 9149-6 has a 1/2" shank. Easy to adjust for wood or composite oars. Adjust for most comfortable rowing length. Attwood Corporation has been an award-winning leader in engineering, testing, and manufacturing the highest quality marine products for over 100 years. We deliver safe and reliable lighting, fuel systems, water systems, seating & pedestals, swim ladders, custom upholstery, and general marine accessories that are easy to install and meet regulatory compliance.