VKmaker UNO Project Smart Robot Car Kit with Four-wheel Drives, UNO R3, Link Tracking Module, Ultrasonic Sensor, Remote, ect. Newest Intelligent and Educational Toy Car for Kids The most economical and newest robot car kit with simple mechanical structure, a nice system and very easy to install. there is a ultrasonic sensor to keep the car way from barrier. 3pcs line tracking module can make the car according to the specific travel. IR receiver assist you control the cay by remote. Best packing and fast delivering We are factory directly selling, if you have bigger orders, please feel free to contact us, we will give you much better prices!