The Duel Autumn Thunder 17" Compact Bugle Call features dual chamber technology that makes you sound more real. And, gets you closer than ever. This 17" bugle gives you a competitive edge over all other elk calls - bugles, or cow and calf calls. Realism has never been more important when you're on the hunt. Those old, mature bulls get call-wise and it's up to you to Get Real. Its different diameter resonating chambers have a more realistic sound. Adjustable single reed produces full range of calls from long range bugles to close-in grunts Includes camo cover, two replacement reeds, two O-rings and instructions.