The upgraded Bullet Belt 2xD offers twice the steady resistance to enhance explosive power during the drive phase of acceleration. This model pairs perfectly with the original Bullet Belt Pop Rip, allowing highly trained athletes to further develop explosiveness over a longer distance during starts. For optimal results, we highly recommend using the Smooth Release method with the 2xD. The coach or training partner simply releases the large handle while holding onto the small handle, allowing the athlete to peel away the double-length velcro tail and accelerate away. Want to increase your explosive speed throughout your acceleration? Look no further than the Bullet Belt 2xD, specifically designed for this purpose!