Material:Natural latex( Kindly to the environment),can be stretched repeatedly,not deformable.
Four levels for different crowd: Purple(81.9*0.2*0.51 inch,15-35Lbs) :For Office Worker,Family Women,Fitness Beginners. Red (81.9*0.2*0.83 inch,25-65Lbs):For Office Worker,Family Women,Fitness Beginners,Fitness coach Green (81.9*0.2*1.14 inch,35-85Lbs):Fitness Beginners,Fitness coach,Fitness Fanatic, Black（81.9*0.2*1.46 inch,45-105Lbs）:Fitness coach,Fitness Fanatic,olympic Athletes.
Application:Pull up assistance,power resistance exercise,GYM stretch training,Yoga exercise,and other strength-training. Use it,You can workout arms muscles, legs muscles,abdominal muscles,and so on.
More cost-effective to buy a set of 4,that save 60% than buy one by one. And, As you get stronger, you need different band of the other levels.
After-sale guarantee:One year quality assurance(We will send you another one,if it is broken for nonhuman reason.). Please contace us if any other qustion.