Product Description Material: galvanized iron Colorsilver Ball material: nylon Ball diameter: 16mm 0.5inch 25mm1inch 16mm Dimensions: 48 x 32 x 20mm (L*W*H) 25mm Dimensions: 75 x 50 x 30mm (L*W *H) Package Includes: 4 x Roller Transfer 8 x Screw 1. PACKAGE CONTENTS: 4 x Nylon Furniture Casters 1 x Screwdriver 8 x Screw 16/25mm diameter round ball transfer the space for installing the transfer bearing roller is small. There are two mounting holes for screw mounting. 2. HIGH-QUALITY MATERIALS: The main body of the furniture ball transfer unit is made of zinc-plated carbon steel which has the characteristics of scratch resistance corrosion resistance rust resistance and not easy to damage. 3. CONVENIENT AND PRACTICAL: Smart and interference-free; The ball can flexibly rotate 360 degrees use smoothly move goods faster and save more time. The maximum load capacity of a single roller is 15kg which is applied to most objects. 4. NO NOISE: The rolling bearing transfer units are polished during the production process smooth surface and no big noise during transportation. This entire ball transfer rolls smoothly and quietly by driving ball bearings.