MDUSA Strength Bands Strength Bands are an incredible versatile tool for adding resistance to stretching, lifting, and bodyweight training exercises. A higher quality band does not exist. Ideal for assisted pull ups and dips. All bands are made of 100% natural latex through a continuous layering process to ensure long life. All bands are 41" in length and 3/8" thick. Six different widths provide a range of resistance levels. Black - X-Heavy - 4" wide The BIG DOG band for power lifts. Resistance is 80 to 200 pounds.