The Attwood Bow Roller 11209-1 is 4 inches long with 3.5" diameter roller ends. It is made from natural rubber to help guide the deep "V" of your boat to the stop pylon and cushion it from jostling on the road. It has a pre-drilled hole for easy and correct mounting. 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.