ABI Standard Design Cartridge Bearings. FEATURES: 90% filled with Mobilux NGLI 2 synthetic grease, dual-lip labyrinth seals If the bearing you are replacing is not marked with a manufacturer number, measure it and compare to specifications listed For some DT, Bontrager and Giant applications Replaces 6903 bearings with 18mm bore in DT Swiss hubs SPECS; Thickness: 7mm Bearing O.D: 30mm Bearing I.D: 18 Material: Steel