Maximize control for different types of loads. These hand trucks can transport boxes wherever they are needed. Transport loads smoothly and evenly over rough or uneven floors. 10″ diameter pneumatic tires are standard on all hand trucks, except for ALUM-H, ALUM-PIN, and ALUM-3-CONV, which are 10-1/2″ tires. 10″ diameter industrial solid rubber tires are also available. The convertible hand trucks also have 5″x 1-1/4″ poly-on-steel swivel casters at the bottom of the handle. ALUM-SG (stair guides) are not compatible with the CONV models. Assembly required.