i used this grunt tube during my last 2 muzzle load hunts and called in a 10 and an 8 point. the only thing i did was turn the plastic reed around inside to make it easier to blow. the way it came in the package had the plastic reed and another half reed in the end you blow in which made you have to blow harder to get the desired grunt. i pulled that reed out and switched it around with the other side that only had the one plastic reed and now can blow alot more gently to produce a "softer" grunt with less force. it worked great. it is the one that is orange.