Premium thick RRder with brake function. Suitable for all types of crib rollers The soft rubber wheel surface does not leave marks on carpets or natural wood and wooden floors, tiles, special floors and tiles. smooth concrete/asphalt floors Dual-wheel design improves weight distribution and smooth operation, makes it easy to slide and pivot Swivel and roll freely and quietly in all conditions maintenance-free directions Easy to install: just click on. These RRder are suitable for a wide range of industrial applications in homes, schools, garages, shops, carts, tables and hospitals. Types: Activation wheel / brake. Product size: 2". Color: black + silver. Materials: stainless steel + rubber. Contents: 2 active wheels. 2 brake wheels. Package contents quoted above only, no other products are included.< /p> Note: Due to the lighting and screen setting, the color of the product in photos and the actual product may be slightly different.The size of the actual item may vary by +/- 1 to 3 cm.