We ordered these wheel exclusively as replacement for Thailand's JUMBO and SUMO Hand trucks. The tread is Brown ThermoPlastic Rubber, so they are guaranteed to roll smoothly and quietly. Compare to the default Black PU wheel, TPR wheel may last 2 times longer.
A real bargain for you: This one is strong and sturdy. Manganese raceway and Dust proof ring are not something you'll see everyday. This one will last very long at minimum maintenance effort. The wheel is soft and protected by 2 covers.