YFROBOT Wheel 130*60mm Pair with 4mm /5mm/6mm/8mm Shaft Adapters

Overview:

Two 120mm diameter wheels can be used as replacement parts or for custom robots that need to navigate complex terrain. The black tires are made of flexible rubber to increase traction, while the plastic wheel hubs are blue and filled with sponge, and not inflatable. The included adapters make it easy to install the wheels onto motors with 4mm/5mm/6mm/8mm output shafts. These wheels are sold in pairs: you will receive two wheels and two adapters.  

wheel size:

adapter  size: