The retractable design of the new generation of heavy equipment rollers. Freely adjustable between 20-32 inches. The maximum extension length is 5 inches longer than that of the previous generation. Suitable for different sizes of electrical appliances and furniture. The mobile base of the washing machine and dryer is equipped with 24 high-quality wheels to increase the stress area with the floor. It has strong bearing capacity and can bear 700 pounds at most.