Not positive but..... The tires seem to be rubber and the wheels are plastic.....I would guess Poly Urethane, thus the PU designation for the wheels. I like mine but I have found some flat free tires will develop a flat spot if left with a load on them. It rounds out later, but it will happen to some of them. Buy them.
According to the description, "800 lbs. dynamic load and a static limit of 900 lbs.", I would say yes. It depends on your gate, ground surface, also, the upper track support.
