Build your forearms and grip strength with Slackers Ninjaline Ninja Balls. Built for their Ninjaline Backyard Hanging Obstacle Course, grip the textured polyresin balls and swing across them like monkey bars. Small diameter is perfect for petite hands. Loose-swinging balls allow full shoulder rotation. Includes two 2.5 Ninja Balls, two 6L x 1W straps and two delta safety clips. Ages 5+. Wt. capacity: 250 lbs. Cancer and Reproductive Harm- www.P65Warnings.ca.gov.