Are you Ninja ready? Made with 4″ x 4″ or 2″ x 2″ steel trusses, our “Katana” Ninja frame accommodates dozens of AG Ninja obstacles to give your gym countless Ninja training possibilities. The Katana frame is versatile enough for younger athletes, but yet heavy-weight and sturdy enough to withstand former college football players at 6’3″ and 230lbs running through our courses. (Obstacles sold separately). No floor anchors required for the 4in x 4in steel. The 2in steel should be anchored to concrete.