This trampoline is an effective, safe, and advanced way to exercise. Solid all-steel frame structure, six removable rubber tip legs and a heavy-duty rebound surface with safety pads. A durable mat can provide excellent jumping performance, the jumping can improve children's exercise ability, promote cardiovascular health, increase heart rate, and minimize the risk of disease. (Please notice the 4.5FT kind of trampoline, the colour of the inner mat is red-black, not blue black)There is no gap between the net and the jumping mat to ensure your safety when jumping. The fully visible net creates a safe and comfortable jumping environment, and you can watch your children outside the net, which gives you the confidence to let your little ones bounce around in peace. Let your child enjoy the jump.