The bag has the shape of an irregular circle which allows for efficient gas transfer in any direction, and thus for maintaining the selected position under water. Increasing the width of the bag and a special insert sewn on the contour of the bag give a good lateral hold of twina in diving with additional cylinders. In addition, the insert increased the capacity of the bag without increasing its contour – a small bag with a large capacity was created. The wide belt at the bottom of the bag allows this extra capacity to be used, providing the diver with a "high" position on the surface of the water. We also maintain a stable position under water thanks to an easy gas discharge. The rear valve was placed "intuitively". Reaching out to the cistern you just hit her. The inflator hose is located centrally so that the hose seat is exactly between the cylinders, which allows the gas to be siphoned with the infaltor without the need for a strong upward tilt. The bag is very narrow in the upper part giving practically unlimited possibilities for the configuration of hoses and machines, and, equally important, free access to the valves. The position of the bag relative to the set and the plate can be determined by selecting one of the two pairs of holes for the screws fixing the bag on the cylinders.