High quality: made of upgraded polyester material, non-sticky, environmentally friendly, non-toxic, and odorless Tensile strength level: The length of each stretch belt is 104cm, and there are three types of tensile force: small, medium and large. The purple one is the smallest, suitable for beginners. Pink has medium tension, suitable for those with a little yoga foundation. Green is the strongest, suitable for more professional people. Durable material: Using high-quality polyester material, it is durable, flexible, light and portable, and can be used well in the gym, office or home. Versatility and flexibility: Stretching training can improve your posture, reduce stress, increase the range of motion, increase endurance, reduce the risk of injury, increase energy levels, improve sports performance, reduce soreness, etc. It is for resistance training, physical therapy and Ideal for sports training.