The overall dimension of the wheel (diameter x width) is 150mm x 24mm / 5.9 x 0.94, the inner diameter of the center bearing is 8mm / 0.3, and the length of the axle screws is 75mm / 2.95. Please check the detailed dimensions on the product image before purchasing. Package includes 2x gray front spare wheels, 2x axles, easy and convenient to install without complicated steps. Made of high-quality and environmentally friendly rubber material, this solid replacement wheel set is anti-slip and dustproof with strong wear resistance and load-bearing capacity. Suitable for use on various mobility devices, compatible with most wheelchairs, walkers, rollators, or other replacement accessories with 6-inch wheels. This front wheel replacement set provides a quiet, smooth, and lightweight ride on all surfaces, suitable for indoor and outdoor use. Economical, practical, and built for long-term use. Specification: Material: Solid Rubber Color: Gray Overall Wheel Dimension (Diameter x Width): 150mm x 24mm / 5.9 x 0.94 Center Bearing Inner Diameter: 8mm / 0.3 Distance Between Bearings on Both Sides: 40mm / 1.57 Axle Bolt Length: 75mm / 2.95 Total Weight: 700g Package Includes: 2 x 6-inch gray front spare wheels 2 x axle screws