Patented StagedBounce technology allow 50% of the springs to engage immediately * JumpSport trampolines are the first and only trampolines designed to reduce the risk of injury directly on the jumping surface * Heavy-Duty frame is made from Cold Rolled Steel that is 1.8 inches in diameter * Tough Jet Black Powder Coat Finish, 10-Year Frame Warranty * Frame Pad is Thick, Blue, and made up of EPE closed cell foam with a strong PVC outer covering * It comes with 50% of the springs engaging a fraction of a second later creating a safer and more forgiving jumping surface