The KILLER SERIES lets you try our best selling mouth calls all in one package. This package includes the THUNDERKLUK, MAMBA COMBO, and the REDHEAD HYBRID. Every one of these calls are capable of getting the job done. We offer all of our mouth calls with the option of low, medium, and high stretched reeds. This gives you the ability to find the best possible stretch for yourself. Finding the right stretched call is crucial and can take your calling to the next level. If you are new to using mouth calls we recommend starting out with the medium stretch. Our medium stretched calls are a great starting point. This will give you feedback and let you know if you need to move to a higher or lower stretched call.