The RobotX Chassis is the latest. It features two gearmotors with 65mm wheels and a rear caster. The chassis plates are cut from acrylic with a wide variety of mounting holes for sensors, controllers, power, etc. Simply bolt the two pre-cut platforms together, attach the motors and caster and add your favorite robotics controller. This kit includes all of the parts needed to assemble the chassis as well as a 4xAA battery holder with barrel jack termination.