The Bipedal Walking Robot is an addition to the Educational Construction Series. Walking Robot moves by transferring its weight. When the weight transfer unit, which is composed of a gearbox and battery case, moves right, and left, the model rocks and its legs move forward. Length: 85mm, width: 132mm, height: 107mm (138mm with guide rod attached) Weight: approximately 138g (including batteries). Two separately sold AAA batteries are required. Continuous running time: about 2 hours. Gear ratio: 114.7:1. Includes low rpm type 130 motor. Speed: about 4.8cm/s (170m/h) (The model moves 1m in about 20 seconds.) Running on even surfaces is recommended. Features light gray plastic parts. The legs and plastic slides have holes to attach parts such as universal shafts, arms, and your original parts by tapping screws. Enjoy changing its appearance! Easy snap-fit/screw-together assembly. Challenge level: 3 (5 is the highest.). Approximate assembly time: 120 - 180 minutes. Robot Movement Crank rotation is converted into reciprocating motion by the slider. Turning Adjusting gearbox attachment angle and limiter alters the model direction. Gearbox attachment angle is adjustable to three directions (right, middle, left), and it can be changed even after assembly. (If gearbox is moved to left, the model turns right.) The legs have limiters to limit model lean. When the limiter is down, the body lean is decreased, and stride length becomes shorter. Attaching guide rod redirects the model if it hits an obstacle. Making the model hold things such as an AAA battery (approx. 11g) changes its center of gravity, which lets the model turn.