The cross sectional height is reduced by 69% in comparison with the Slim Type Crossed Roller Bearing CRBS, previously the slimmest. The width is also as small as 5 mm and the cross sectional area is reduced by 43% in comparison with conventional products. Also, the mass ratio is 0.38, realizing significant weight saving in comparison with CRBS. (compared with a product with bearing bore diameter of 50 mm)