Expanding-Sleeve Stem—Stems with expanding sleeve have a rubber sleeve that expands as the nut is turned compressing the sleeve.

Expanding-Wedge Stem—Stems with expanding wedges have metal wedges that expand outward when the nut is turned for a more secure fit than stems with expanding sleeve.

Tread-on-Core Wheel—Tread-on-core wheels have a polypropylene core that is harder than the tread, balancing strength with cushioning.

Soft—Soft and medium rubber wheels are shock absorbing and provide good traction on rough surfaces.

Wheel Brake and Swivel Lock (Total Lock)—Casters with total lock brake the wheel and lock the swivel with one press of the foot pedal.

Ball Bearings—Ball wheel bearings are the easiest to roll.

Sealed Bearing—Sealed bearings are completely sealed for the best protection against dust and debris.

Sleeve—Sleeve wheel bearings prevent wear to the wheel bore but don't roll as easily as other bearings.