The Unstoppable Bug Robot Kit (TUBR) is really a bug with an attitude and an electronic brain. It just can't be stopped! If you put a box, object, or if there is a wall in front of the bug it has a powerful infrared detecting system that “senses” the obstacle and causes its simple brain to change direction. Features 2 motors, a bright red LED eye, a transistor/relay brain and 2 built in rechargeable batteries. Black plastic bug body is approximately 3 3/4” L x 1” W (excluding arms which have small motors attached). Operates on any smooth surface such as a table, floor, desk, etc., when quick charged from a 9V battery (not included). Complete with all parts, PC board, bug body, motors, and instructions. Skill Level 2.