1. The wheel of the transfer trolley are special manufactured by cast steel and rubber. The rubber will reduce the impact force to the ground from the trolley, and protect the damage to the wheel.

2. The wheels of the towed trolley has been sealing treated to protect them from water, oil and dust.

3. The turning of the trolley is controlled by the tow bar, and then connects to the four wheels, which has shorted a lot for the turning radius to make the trolley available in small space.