Practical and helpful- Ankle resistance bands application for football/tennis/baseball training ,physical training and home workout.It is helpful for the people who want to increase speed and agility Effective resistance training - Strenghen legto improve running speed, vertical jump, mobility, endurance. Especially great in short burst sprints training and dynamic agility drills Suitable for all types of people - Ankle Straps by athletes, coaches, trainers, physical therapists, and healthy minded people of all ages Elasticity and resistance - Elasticity variable,The tensile strength of the Resistance Bands is about three times,2x Elastic rope total 40LBS,about each 20LBS.You can choose the Elasticity which suitable for you Material - hidden Natural rubber latex, heavy duty clips