Bearing NO.    Boundary dimensions(mm) d    D    B RLS4    12.7    33.34    9.525 RLS5    15.875    39.69    11.11 RLS6    19.05    47.63    14.29 RLS7    22.225    50.8    14.23 RLS8    25.4    57.15    15.88 RLS9    28.575    63.5    15.88 RLS10    31.75    69.85    17.46 RLS11    34. 925    76.2    17.46 RLS12    38.1    82..55    19.05 RLS13    41.275    88.9    19.05 RLS14    44.45    95.25    20.64 RLS15    47.625    101.6    20.64 RLS16    50.8    101.6    20.64 RLS18    57.15    114.3    22.23 RLS20    63.5    127    23.81 RLS22    69.85    133.4    23.81 RLS16 Deep Groove Ball Bearing Open - Imperial 50.80x101.60x20.64 (2"x4"x13/16") - Budget Brand Deep Groove Ball Bearings are the most common bearing type found in a wide variety of applications. Versatile and robust they are available in a wide range of sizes and options including seals, shields and special clearance for high speed applications. The main types are: Open - Bearing without seals or shields, suitable for applications where lubricant will constantly flow through them i.e. gearboxes. Metal Shields - Bearings fitted with steel shields and lubricated for life. Rubber Seals - Bearings fitted with steel reinforced rubber contact seals which provide a better seal but add friction so are unsuitable for high speed applications, lubricated for life.