Center Hub Design. This black tread wheel is a light weight, high performance hand truck wheel that rolls longer, quieter and smoother without marking floors. The exclusive wheel design features a zerk fitting for the wheel bearing and provides maximum rolling ease for greater maneuverability on the job. The exclusive wheel tread material won’t pick up gravel or floor debris, and this wheel performs better than a pneumatic tire…yet never goes flat! Like all of our Performa models, the wheel provides maximum shock absorption for a cushioned ride and will not flatspot… even under load. The materials give superior weather resistance and lower temperature flexibility, as well as a high resistance to chemicals, acids, water and steam.