This is a set of 4 aluminum double row omni wheels. They have been used on a prototype model and show a little sign of use but still have plenty of life left. This wheels come with bearing rollers and lock collars as shown in the picture.
This is a direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels. It is an Arduino robot platform for indoor robotics. It can vector in any direction. Includes a choice of Arduino for making a great Autonomous Robot.
Steel Machine Key 3/16" x 3/16", 3/4" long. These keys are economical with high strength and will fit 3/16" keyways.