Features: Brand new and high quality Wear-resistant, strong hardness, wear-resistant, smooth rolling, high hardness, strong load-bearing, precision machining and good coordination High hardness, firmness and durability, high-strength medium carbon steel precision machining, smooth surfaces without burr, uniform stress, beautiful appearance and smooth design. Coaxiality, flatness, accuracy, coordination, high hardness and strong load bearing. It adopts numerical control equipment to ensure the flatness of each part and the concentricity of the bearing, and ensure the smoothness of the printer after multi-wheel loading. High-quality bearing steel rolling bearing, smooth rolling and low noise, embedded bearing stainless steel bearing, low resistance, smooth running, high printing accuracy and lower noise. The load-bearing capacity is 1256kg. Suitable for indoor doors, wardrobes, cabinets, sliding doors, etc. Small wheels are suitable for various use scenarios, such as home, office, indoor, factory, garage and so on. Specifications: Material:Chrome Plated Steel Diameter: 30mm Length: 200mm Tolerance: 0.01mm Processing material: iron, S45C Surfaces roughness: RA0.8 Processing methods: cutting, welding Size:Approx.10x1.5x8cm/3.93x0.59x0.31inch Package Includes: 1x Trolley Assembly Roller note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.