caster wheels

Casters are a general term that includes movable and stationary casters. Movable casters, also known as universal wheels, are built to allow 360 degrees of rotation; Fixed casters have no rotating structure and cannot be rotated. Usually two kinds of casters are generally used with, such as the structure of the trolley is the front side of the two fixed wheels, close to the back to push the handrail is two activity universal wheel.