Storus SuperHorn is the loudest breath powered horn on the market. It never has to be refilled and you never have to replace any batteries because it runs on an unlimited resource, your own breath. If the membrane breaks or gets too quiet, you can use the two replacement membanes or buy more Just place your lips on the hold on the side of the cone and blow. Warning membrane is made out of synthetic or latex rubber and comes with two replacement membranes. It is perfect for the outdoors and can be used for rescue, to scare large animals, sporting events, parties and more. It measures 6.75 inches long by 2 inches in diameter and weighs only 2.6 ounces. The SuperHorn is the loudest breath powered horn on the market. It produces a superhuman blast of sound. The Super Horn is essential for many activities. It can be used as a life saving device when camping or hiking, to scare large animals away, at sporting events or at parties and celebrations. It never runs out or requires refilling because it uses an unlimited resource... your breath. It is simple to use. Just place your lips around the hole found on the closed cone and blow. You can easily replace the latex rubber if necessary. Extra membranes are provided. It measures 6.75 inches long by 2 inches wide by 2 inches deep. Other color options available by Storus and Mosaic Brands Inc. Caution: do not blow directly into one's ear. May cause damage. Membrane is made out of synthetic or latex rubber and some may be allergic to latex.