The BERG Grand Champion is the biggest trampoline range from BERG with the benefits of both round & rectangular trampolines. With a robust & sturdy steel frame, the quality is shown through the 13 year warranty with the frame. Rust-protection is provided through a zinc layer on top of the steel, which is then further protected by a black powder coat finish; also giving the frame a stylish black finish. This rust-prevention technology extends the life of the frame as rusting can cause weakening of the joints. For extra jumping space, the enclosure poles are rounded to give your children more room to play & jump around! Twinspring technology also comes with this trampoline. Due to the layout & design of the springs, jumping bed & frame, BERG have managed to increase the number of springs by 30%, giving the user more spring in their bounce! Not only does the large number of springs increase the bounce, but due to the Twinspring technology, the springs are longer with extra coils, making them more flexible, ultimately giving you more bounce than your standard trampoline.30mm thick spring padding helps to cushion the impact if your children were to come into contact with the spring or frame area. With a width of 380mm, the spring padding also covers more of the springs than a standard trampoline & helps to prevent trapped fingers & legs between the springs.