High-quality Resistance Bands: The resistance bands are made of 100% natural latex material, which provides strong wear resistance so that the bands are durable, extremely stretchable and environmentally friendly. You don't have to worry about the bands tearing, fraying or damaging your skin. 4 Different Resistance Levels: The pull-up assist bands have 4 different resistance levels: Red (15-35 lb: Beginner level), Black (30-60 lb: Advanced level), Purple (40-80 lb: Senior level), Green (50-125 lb: Professional level). You can choose the most suitable resistance level for separate stretching or combine the exercise bands for higher intensity training. Help & Fitness Effect: Whether you are a beginner, experienced sports enthusiast or fitness professional, everyone can use these fitness bands for pull-ups, stretching exercises, squats, yoga or other exercises to strengthen your strength or do professional sports training. These exercise bands will help you get more effective training results! Wide Application: The exercise bands are perfect for many types of exercises and places. You can use them for pull-ups, strength training, push-ups, barbell assistance or stretching strength training at the gym. You can also do simple exercises with them at home, in the office or in other indoor places. The exercise bands are really a good choice for daily exercise. Portable: These exercise bands are so compact that they practically do not take up any space or weight. They are easy to store in a storage bag and more convenient to carry with you.