Specification AgeRangeDescription : adult Brand : uxcell BulletPoint1 : TWO RUBBER SEALS FOR DUSTPROOF: These ball bearings are dust-sealed with two rubber seals to prevent the ingress of dirt, water, and foreign matter. BulletPoint2 : FEATURES: For linear bearings, nickel-plated surfaces can increase their wear resistance and corrosion resistance. The built-in nylon cage in the bearing makes the entire linear bearing lightweight, operates with low noise, extends bearing life, and has good lubrication performance. BulletPoint3 : SIZE for LINEAR BEARINGS: As parts of linear motion systems, the linear bearings are used in conjunction with cylindrical shafts or guideways.,Length: 30mm /1.2inch; External diameter: 21mm /0.8inch; Internal diameter: 12mm / 0.5inch; BulletPoint4 : FUNCTION: Linear bearings are linear motion systems for use with cylindrical shafts with infinite stroke. Since the carrier ball is in point contact with the shaft, low loads are applied. The steel balls rotate with very little frictional resistance, which results in a smooth motion with high accuracy. BulletPoint5 : WIDE APPLICATION: Linear bearings are widely used in electronic equipment, tensile testing machines and digital three-dimensional coordinate measuring equipment and other precision equipment, as well as multi-axis machine tools, punch presses, tool grinding machines, automatic gas cutters, printers, and other industrial machinery sliding. As parts of linear motion systems, the linear bearings are used in conjunction with cylindrical shafts or guideways. Color : Silver Tone ExternallyAssignedProductIdentifier : 7610763629771 ItemName : uxcell 4Pcs LM12UU Linear Bearing 12mm Bore 20mm OD 29mm Length Linear Ball Bearings Nickel Plated Surface Double Side Rubber Sealed Bearing Steel for CNC Machine 3D Printer ItemPackageDimensions_Height : 1.97 inches ItemPackageDimensions_Length : 5.12 inches ItemPackageDimensions_Width : 3.15 inches ItemPackageQuantity : 1 ItemTypeKeyword : linear-ball-bearings Manufacturer : uxcell ModelName : OQATNXUR ModelNumber : OQATNXUR NumberOfBoxes : 1 NumberOfItems : 1 PartNumber : a24073100ux0156 ProductDescription : Description: 1. Provides linear Ball Bearing with seals on both sides to prevent ingress of dirt, water, and foreign matter. 2. Linear Motion Bearing (also called Ball Bushing or Shaft Guiding) is a rolling friction supporting element that is usually used for linear motion mechanical parts with small friction. 3. Coordinate with Linear Motion Shaft, recirculating balls provide unlimited stroke at low friction movement 4. It is great for 3D printers, CNC, and other applications.