"Multi-function for strength training, stretching, muscle reeducation training, coordination training, endurance training and core exercise. Simple to use and portable enough to take anywhere. Provides both concentric and eccentric force on the muscles, improving strength, range of motion and coordination. May be used to train a single muscle group or multiple muscle groups. Color-coded, progressive resistance from yellow to silver. Assists muscle performance. Varying band thickness for increasing resistance levels."