This Unicycle has a 20 inch diameter wheel. A stong durable learner or intermediate machine. Steel based seat with durable vinyl cover. Sealed bearing held in split bearing housing (these are more robust than Raleigh type unicycles with lollipop bearing housings). Comes with quick release as standard, 25.4mm seatpost. UDC wide flanged CroMo hub. Robust Plastic block pedals.