The 737 NITRO Canada Goose call offers a style based on the design, shape, and size of the popular 737 Duck Calls. It is an easy-to-blow, extremely responsive short reed call that features a broken in guts system. The NITRO is a very versatile call which offers beginners to experienced callers the ability to achieve nasty lower end clucks all the way up to high volume Canada goose chatter. Like all 737 calls, the NITRO is hand tuned and features a lifetime warranty.