These are two brackets that can mount to the bottom of the Trekker to hold photo reflectors. Black and white contrast disks are included that can be read by sensors to allow the microcontroller calculate how far the robot has traveled.
This is a Pre Built direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels and hubs. Its a Arduino robot platform for indoor robotics. It can vector in any direction. Customized version of TP-142-004.