Rat-holing is a phenomenon that frequently occurs inside bins or silos with certain materials. Due to the physical and chemical properties of the product, the central material column drops instantaneously as soon as the silo outlet valve is opened, while the surrounding material remains immobile. Especially with light materials a PG-type GUNJET Air Cannon is often the ideal solution for such inconvenient situations. Other applications are the corners of rectangular-shaped bins where because of tiled walls or inserts, hammering or vibration on the outlet sections is unsuitable. GUNJET Air Cannons are also successfully used in cases where bridging occurs.