Anpro resistance bands are made of 100% natural latex, it's safe and durable. You can do workout using only one band or two different bands. They offer effective strength-training, it can workout your arms, back, shoulders, legs, and butt all at once with mobility band, which is perfect for for body stretching, power lifting, resistance training, yoga, and physical therapy to help strengthen torn ligaments or muscles. The best choice for daily workout. There are 5 power levels to meet your requests: 1 x Yellow Band: 2080mm x 6.4mm x 4.5mm/81.9 x 0.25 x 0.2in/58g/2.04oz/8-15lbs; 1 x Red Band: 2080mm x 13mm x 4.5mm/81.9 x 0.5 x 0.2in/101g/3.57oz/15-35lbs; 1 x Black Band: 2080 x 22 x 4.5mm/81.9 x 0.9 x 0.2in/187g/6.6oz/25-65lbs; 1 x Purple Band: 2080 x 32 x 4.5mm/81.9 x 1.3 x 0.2in/284g/10oz/35-85lbs; 1 x Green Band: 2080 x 45 x 4.5mm/81.9 x 1.7 x 0.2in/385g/13.56oz/50-125lbs