The prototype was manufactured by NutriVet Company from a concrete KARI network with a stronger wire (ie, with a diameter of at least 6 mm). The 2 x 3 mesh was cut lengthwise and the two parts were then joined together by the wire to form a circle. A silage sail was poured into it. In the resulting space, the stewing slice remains to the edge, and the sail overlaps over it so that no air can penetrate into it. As a load, load bags are used over the entire sail top or a round bundle of straw.