XRAY has released Ball-bearing 1.5x4x2 Steel Sealed Oil 4 under Metal Bearings category
Top-notch ball-bearings ID x OD x level (mm) = 1.5x4x2mm. Pair of 4 pieces. These ball-bearings are degreased and carefully oiled with AeroShell Fluid 12 oil for maximum smoothness, longevity, best restriction and maximum performance.