I have two that are my go to friction calls. I have 30 I bet but have 2 that work, and work amazingly well. One is made by Darin Dawkins out of Rock Hill, SC it has an aluminum surface and is very sweet with a great breaking yelp. Deadly when birds want shy quiet hens.
The other is a call made by RJ Custom Calls out of GA, and it is also Aluminum. It is much raspier and breaks from a high end to a good rasp, absolutely deadly on hard gobbling birds which are really fired up.
I do use a slate some, but it isn't like any slate you can buy in a store, it is small (skoal can size), but deep probably 3 inches or more, the sound chamber is deep and it has a very subtle hollow yelp which is lethal on roosted birds.
SOme of the others I carry are a Woodhaven Vision Aluminum, and Vision Crystal. They are okay, but not nearly the grave diggers the others are.
Just my opinion, fwiw, but there is absolutely no comparison to the reactions I can get from aluminum versus every other surface out there. And not all aluminums are created equal, most are junk.
