##Enduro ABEC3 6803 Wheel Bearing 17x26x5 (Single) One of the most common bearings for front or rear hubs, the Enduro ABEC3 6803 Wheel Bearing 17x26x5 (Single) is labyrinth sealed with two NBR 70 full-contact, medium-high friction seals, which ride in a groove machined into the bearing. Combined with marine grease, this seal creates an almost impenetrable barrier to contamination. High precision, Grade 10 chromium steel balls are within 10/1,000,000″ round, twice as round as the industry standard. These precision balls ride in a 52100 high carbon chromium alloy race, hardened to R-62 to make them extremely tough and durable. Mirror finish polishing of the races creates ABEC-3 precision and noiseless movement. When replacing a bearing, measure the inner diameter (ID), outer diameter (OD), and width (W) to determine compatibility.