This is a set screw lock collar. It is for a 0.3125 or 5/16 inch shaft. They are steel and zinc coated. Perfect for keeping your shafts or bearings in place.
Shaft Collars (sometimes called lock collars) are easy to install; the collar provides an easy way to keep your shaft from sliding or your flanged bearing from coming out.
A master battery disconnect switch is a lever-operated battery cutoff switch that will disconnect power for the battery circuit.
This is a direct drive 4WD robot kit that uses Nexus mecanum wheels. The mecanum wheels allow it to vector in any direction.