K’nex building systems are dynamic and open-ended, and let kids learn about science and engineering while building cool, motorized gadgets. This set of four Robo Battlers—Ace, Flash, Slasher, and Stomper—each come with about 120 parts and motors that enable unique movements. Kits can be combined to create bigger robots.

WARNING: CHOKING HAZARD—small parts not for children under 3 years.

For ages 7 and up. Two AA batteries per kit, not included. Approximately 9"W x 9"H.