DEEP GROOVE BALL BEARINGS. A MINIATURE BALL BEARING IS A TYPE OF SMALL ROLLING ELEMENT BEARING THAT USES ROLLER BALLS TO SEPERATE TWO BEARING RINGS OR BEARING RACES. THEY ARE PRE-LUBRICATED AND RUBBER SEALED ON BOTH SIDES. PART NUMBER 625-2RS C3. ID: 5MM OD: 16MM THICKNESS: 5MM.