This adapter sleeve provides a mounting interface between a shaft and a bearing bore, allowing the bearing to be fitted onto plain shaft sections without a stepped seat. It has a bore diameter of 20.0 mm and a net mass of 0.074 kg, corresponding to the standard design version, symbol H305. The sleeve enables mechanical fixation of the bearing on the shaft through a tapered fit, transmitting clamping force evenly along its length once tightened. This design simplifies mounting and dismounting compared to a direct interference fit, and is suited for applications where the bearing needs to be positioned at any point along a cylindrical shaft rather than a precision-ground seat.