Use as replacement nylon flange bushing (aka flange bearing) for Perception brand kayaks circa 2000 (give or take a couple years). Reduces a 1/2 inch hole to 3/8 inch hole. Part Dims: 1/2 inch O.D. 3/8 inch I.D. 1/2 inch long. These older version Perception kayaks will take two, one top and one bottom. Fits into the molded rudder bracket on the stern. Rudder pin will be loose without them. Inside diameter is 3/8 of an inch. Fits the old and modern version Perception rudders with a 3/8 inch rudder pin. This part may be used as a spacer in some custom applications.