Andux Land Assisted Stretch Pull-up Resistance Bands Crossfit, Gymnastics TLD-12 Increasing Speed, Improving Vertical Jump,Alleviating Back Pain,Physical Therapy,Strength Training. Exercise Bands for Assisted Pull Ups, Chin Ups, Muscle Ups, Ring Dips or Power Lifting * Strong and Durable. Economical, costing less than monthly gym membership fees. Manoeuvrable, so you can easily control the resistance. Effective, increase muscle strength and decrease body fat.Portable, allowing you to workout anytime and anywhere.