This is an OS Max Bearing for many engines such as: 61SF, 61SFN, 61FX 91FX FT300 FR5-300 INCLUDES: One Rear Bearing _ SPECS: Inner Diameter: 17mm Outer Diameter: 35mm Width: 8mm Bearing Markings & details: JAPAN UX NTN 18003OS EnginesPart OSM29030001 BOX DIMENSIONS: 2.13" W. X .38" H. X 3.50" L. BOX WEIGHT: .08 LBS.