Invincible Marine Bow Stop Roller, 3-Inch x 3-Inch, Black Rubber Made using the highest quality components Performance and quality tested The most trusted name in marine accessories and equipment Acts as a bow stop for the boat Allows your boat to roll smoothly on the trailer and spins freely to reduce drag while launching your boat Unaffected by oil, gas or salt This roller is 3-inches by 3-inches in size and made of black rubber Comes with a 1-year warranty