The new OnneX Clicker is a completely new evolution of using a thumb button. Working with Joel Turner of Shot IQ, we were able to create the best combination of a thumb button with the huge benefits of a click. The proven Shot IQ techniques to calm the aiming and shooting process work perfectly with the OnneX Clicker!INCLUDED IN THE PACKAGE: Interchangeable 3 or 4 finger pieces, 2 different thumb barrel extension lengths made from Stainless Steel, and 2 thumb barrels, small and a large both made from stainless steel.