This handmade Sportman's whistle is made from a once fired .223 / 5.56 cartridge. It has been cleaned and polished, hand notched, and soldered. It creates a loud ear piercing whistle at 90 decibels. There are 4 options to choose from. The plain whistle fits in your pocket or just about anywhere else. Or there are three other versions that can be attached to your keychain, jacket or bag zipper, and many other places. One has a fishing lure swivel and snap soldered into the primer pocket, another has a loop of 4 strand paracord coming out of the primer pocket, and the third has a loop soldered in the primer pocket with a 1/2" key ring attached. These whistles are all metal, very durable and waterproof (just drain the water out first :). Great for hiking in bear country, or emergency whistles.