The RMHC Spellbound Helps you Bring Them in This call will let you bugle like a frustrated bull challenging for the herd or for the estrus whine of a cow in heat to draw them in. The call is made on the Golden Tone Plate (GTP) frame. As a diaphragm call it keeps your hands free for the shot. Rocky Mountain Hunting Calls Specifications and Features: Manufacturers Number 139 Display Bull Elk Bugle Aggressive Estrus buzz or whine of a cow in heat Advnced skill level Latex Blue