Children expand their STEM skills as they assemble a smart robotic crab with this easy-to-use kit! Kids just use the materials from the kit to build a crab robot that will scuttle to the edge of a surface and make swift turns to avoid falling off! Kit includes over 20 pieces needed to assemble the robot, plus a detailed assembly guide. Chassis with motor measures 4" long. Requires 1 “AA” battery (not included).