Radial/Deep Groove Ball Bearing - Round Bore, 17 mm ID, 40 mm OD, 12 mm Width, Two Contact Seals, C0 Internal Clearance Super finished raceways Quiet operations ISO standard interchangeable dimensions Electric Motor Quality (EMQ) Contact seal(s) offer superior lubricant retention and bearing protection from contaminants Most bearings in this series up to 60 mm bore can also be made available in stainless steel (AISI 440C material).