The AMP green elk diaphragm is a great all around call. This is a single blue reed that produces medium cow sounds, along with producing medium bull sounds.
The green tape is slightly stiffer than normal and has a bitter taste.
"I thought I had my go to diaphragm, but wanted to try a few Phelps game calls. I bought the grey and green to try them out. I prefer the grey for bugles, and more whiny, estrus cow sounds. However, for me, the green is the best all around diaphragm I have ever tried. I feel comfortable making any sound with it, and it will be the call I keep on me at all times this year. I am definitely going to buy more of these. Even if you think you already have your favorite diaphragm, I highly recommend giving Phelps calls a try."