Omnidirectional Mecanum Wheel, RC Robot Aluminium Alloy Omnidirectional Mecanum Wheel with Gold Nuts 4 in Omni Wheel 4 in Omni Wheel

The dimensions say 4". Right. They are only 2". I'll keep returning them until they send what they promised. Zero profit margin on these wheels.

This wheel set worked nicely for our robot. I did need to go through each axle(?) and tighten each nut and perform some slight bending. Keep in mind that these are just over 2" in diameter, so they're small.