Line Follower Robot Kit JSumo روبوت تتبع خط ج سومو JS5230 Aluminum - Silicone Wheel Set (52 x 30mm - Pair) These wheels produced by handmade in best quality. PERFECT for wood dohyo (non-magnetic) sumo robot projects. Outside diameter is 52 mm, thickness is 30mm. Center hole is 6mm, so it fits to all 6mm shaft diameter motors. Inside aluminum rim is processed at CNC lathes. Each wheel's weight is 48 grams. Better for 2 wheeled and 4 wheeled sumo robots. Also suitable for explorer style robots. It has an M4 set screw inside, so It holds motor's shaft mechanically and firmly. - Pid Based Line Follower Robot Kit (Without Battery) Arduino Uno R3 (SMD Clone) x 1 Ardumoto Dual Motor Driver Shield x1 QTR8-RC Line Sensor x 1 12V DC Gear Motors x2 High Grip Silicone SLT20 Wheels x2 Lexan Laser Cut Line Follower Robot Base x1 Plastic Motor Brackets x 2 Female-Male Cable x 10 M3 & M2 Screws & Nuts. Brass Standoffs x 4 JST Cable for Battery Connection Mini Switch x 1 Required Line Follower Path: Black surface, White Line. Generic white electrical tapes (19-20mm width) are a suitable choice for line making.