The Multi-Pack Light Resistance Bands include 4 different strength-resistant bands. Made from durable latex, these resistance bands aid in pull-up assistance, add resistance to stretches and body weight exercises, and add resistance to the barbell for a variety of lifts. Each set of resistance bands measures 41-inches in length and features the Titan Fitness logo. The yellow bands (2-5 lb. resistance) are for light resistance for stretching or bending exercises. The Red bands (5-35 lb. resistance) are for medium resistance for strength training or calisthenics. The Black bands (10-50 lb. resistance) are for strong resistance for light pull-up assistance or strength training, and the Purple bands (25-80 lb. resistance) are made for ultra-resistance for intermediate or light-weight beginners with pull-ups.