Recreational and fitness trampolines are the most common style customers purchase for their personal use. Both styles are available in spring and spring-less designs. Trampolines are typically made of steel, this material makes weather-treating simple and easy, it also provides a sturdy base for safe jumping. Fitness trampolines or mini trampolines, are designed to be used by one person at a time and are intended to elevate the heart-rate through intense movements, similar to step-aerobics. Their small size allows for easy storage, simply slide under a bed or put away in a closet when not in use. Choose Alibaba.com you will find more good products and find your favored trampolines.