Unlike standard bearings, Blueseal Bike Bearings™ are bike-specific bearings, designed to withstand the unique challenges faced by a bike bearing. ABEC 3 rating, a complete fill of premium waterproof grease and close-contact rubber seals makes Blueseal Bike Bearings™ the obvious choice for bicycles. 

N.B. Many other bearing manufacturers add extra numbers to their codes or follow them up with other letters e.g. 2437 2RS or MR2437 VRS. These are just slight variations to the code and not the spec of the bearing. If the dimensions match then they are the same bearing. i.e. 61803 VRS will be the same as 6803.