Different degree of hardness: Each is made of thick thin thick rubber strap. With this tool you can that the firmness and the training intensity for any ganz personally wording if you wish. Red 0.5 mm (Medium)/Blue 0.7 mm (strong)/Green 0.9 mm (strong)/Black 1.1 mm (strong) Professional Flexible Fitness straps: these resistance bands are suitable for men and women of all fitness levels. You can use each band is individually or more bands together to the matching resistance for you. The straps and tools, such as straps or handles are attached carabiner on get the elements you want and the training session. Safe: with this set you can have a full body workout, varied and your legs, buttocks, hips, chest, back, back, shoulders, arms etc. you your body, take you to achieve results, Beleiben you fit and to reach the fitness goals. Number of uses: deal for Yoga, Pilates and improve ideal, strength and range of motion. Use the resistance bands can be the stabilising muscles strengthened, what can risk of bodily injury and rehabilitation after injuries. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.