This Lego sumobot/ battlebot can be built using the Lego Mindstorms EV3 31313 retail set's parts. It features a front flipper, wide rubber tires for good traction, and the EV3 Infrared Sensor for manual operation via the EV3 Remote Control. The .EV3 project file for Remote Control is on Bricksafe: www.bricksafe.com/files/dluders/CustomRemote.ev3 . The EV3 Color Sensor allows for the robot to back up when "seeing" the perimeter line around the Lego Sumo ring. As an option, the pair of red 2L Technic Axles allow for mounting the Mindsensors "Sumo Eyes" to run the SuGObot program ( www.sugobot.com/ev3_download.htm ).