Rubberbanditz Combo Pull Up Assit Bands | Heavy Duty Resistance Exercise Bands for Powerlifting, Mobility, and Stretching LASTING DURABILITY | Our 41" latex fitness bands are made with quality and comfort in mind. Made of natural rubber latex - 99.998% free of soluble proteins - they can streth up to 2 1/2 times their orignal length. The heavy duty wear-resistant design stands the test of time COMBO SET + e-Guide | Includes Medium Band (20 - 35 lbs), Heavy Band (30 - 50 lbs) PLUS free e-Guide with every purchase! LIFETIME WARRANTY | We stand by the quality of our products and offer a lifetime warranty; if for any reason you are not satisfied with your resistance bands, simply send them back for a full refund or replacement. ULTRA VERSATILITY | Our unique 41 closed loop bands work for assisted Pull Ups, Powerlifting, Physical Therapy, Pilates, Calisthenics, Target Stretching, Toning Exercises and Full-body workouts. There are 200+ exercises with these resistance bands WHICH BAND IS RIGHT FOR ME | Our band guide is located in the product images and offers assistance selecting the tension level that is right for your workout - To increase the intesity level, simply combine multiple workout bands to customize the level of tension (Name): (Thickness) - (Approximate Resistance) Light Band: 1/4&#034; - 5 to 15 lbs (2-7kg) Medium Band: 1/2&#034; - 20 to 35 lbs (9-16kg) Heavy Band: 3/4&#034; - 30 to 50 Lbs (14-23kg) Robust Band: 1 1/8&#034; - 40 to 80 lbs (18-36kg) Power Band: 1 3/4&#034; - 50 to 120 lbs (23-54kg) Strong Band: 2 1/2&#034; - 60 to 150 lbs (27-68kg) Monster Band: 4&#034; - 80 to 200 lbs (36-91kg)