This 3 pack of diaphragms feature the best latex we have been able to specify. They have all feature the same latex with differing stretches. #1 will be the loosest, #2 will be a medium stretch and #3 will be stretched for location bugles. Pitch Black 1: Has a looser stretch for easy cow calls and all of the bull vocalizations Very easy to use and quiet when needed Pitch Black 2: Has a medium stretch similar to the popular Maverick and Phelps Signature diaphragms This is a do it all call Pitch Black 3: Stretched tight for ear piercing location bugles as well as higher pitched cow/calf sounds The best thing about this call is the life you get out of it