Up for auction is a set of 6, New TeamTiki MCW  4" robot wheels.

These wheels have been custom modified with a 3/8"-24 threaded bore.   These wheels screw directly into the spindle of most cordless drill motors (in place of the drill chuck)  making a low cost and high power robot motor/gearbox/wheel solution. 

Wheels are about 4" diameter,  1" wide and 5 oz each.

MCW - have a Medium traction compound.  Medium durability and Medium traction/grip.  Running on rough concrete or black top will wear  these wheels,as will combat.  They provide good traction on compacted dirt and carpet.  Not as grippy or as soft as the popular colson caster , but a good trade off vs the cost.