These wheels are manufactured in the best quality handmade.
It is PERFECT for wooden dohyo (non-magnetic) sumo robot projects.
The outer diameter is 52 mm and the thickness is 30 mm.
The central hole is 6 mm, so it fits all 6 mm diameter engines.
The aluminum wheel inside is machined on CNC lathes.
Each rim weighs 48 grams. Better for two-wheeled and four-wheeled sumo robots. It is also suitable for explorer style robots.
It has an M4 screw in it, which keeps the engine's shaft mechanically and firmly.