You are looking at a sprocket that is made for driving the seed meter. These are BRAND NEW take off that have never seen any field use. They fit a 3/4 inch Hex drive. They are 20 tooth sprocket and accepts a #41 chain. This sprocket fits a lot of different planters ranging from the 8100 Series all the way to the 9800 series. Please be sure to make sure this is what your planter takes. 31 available (White, Massey, Agco, Challenger, Corn Planters) (FREE SHIPPING!! to US lower 48) $25.00 OBO List New $50.00 save $25.00!!!