XRAY item 930154 - Ball-bearing 1.5x4x2 Steel Sealed Oil 4 Metal Bearings
Top-notch ball-bearings ID x OD x degree (mm) = 1.5x4x2mm. Set of 4 pieces. These ball-bearings are degreased and very carefully oiled with AeroShell Fluid 12 oil for optimum smoothness, longevity, most useful limitation and maximum performance.