Pull the lever up and the air is filled in large or small amounts as needed. Push the lever down and the air is released, regardless of body position. With its built-in i3+ filling and deflation system, adjusting your buoyancy has never been easier than with this BCD. A thin internal strap rack that secures the BCD tightly to your body prevents the cylinder from shifting on your back. It distributes the weight evenly by keeping the cylinder closer to your centre of gravity, making it easier to dive with a good trim. The wing/bladder tightening system makes you more streamlined and reduces resistance in the water as you swim.