Ball Insert Bearing – Round Bore. 40 mm ID. 3.1496 in OD. 56.5 mm Width. Eccentric Collar. Technical details (XL-KRR-B) XL=X-Life. KRR=Lip Seals on Both Sides (R Type Seal – Has A Zinc Plated Inner and Outer Cover. Between the Covers There Is an NBR Seal Lip Running on A Ground Shoulder). B=Bearing with Spherical Outer Ring.