This system includes everything you need to create a variety of elk sounds and can be used as a diaphragm, or the Sure Fire Bugle Adapter for an easy, versatile elk calling system!a Includes Sure Fire Bugle adaptera Includes Black Magic mouth diaphragma Includes Wapiti Whacker Bugle tube featuring the V.E.T.T. systema Allows the user the option of calling with the Sure Fire adapter or the Black Magic diaphragma Includes camo cover and lanyardMOUTH OPENING: 1 12" / Length: 20"