Our products of non-standard new one caster bearings, the quality casters have been significantly improved. One bearing have the advantages: 1. Only one of a wheel bearing 2. Inner race and the outer has a double roller, double row ball plus retainer mounted to the wheel rotation flexibility. 3. Easy assembling and statistics 4. Wear and impact resistant side 5. According to customer demand plus two seals to prevent dust, debris and the infiltration of corrosive liquids, harsh environment in normal operation. Product specifications include shaft diameter, shaft length, sleeve length, sleeve diameter. Specifically explained as follows: Shaft diameter: the diameter of the screw Shaft length: the distance between the inner wall bracket Sleeve length: width of round bone Sets the diameter: the diameter of the hole wheels