The best howler kit on the market comes from Ed Sceery (if still available). It comes with a good howler and the best instructional video you will find. After learning from Sceery's video I found that E caller sounds were not even using the correct howls as the label said they were. Howling involves speaking a more precise language than distress sounds.
Randy Anderson videos are also good, but everybody has them now that he partnered with Primos. I bought his first videos from a catalog out of Nebraska before most people knew he existed.
Just to give you a heads up, it is all instructional and not so much a hunting video. I would never have attempted howling without it. It wouldn't hurt me to watch it again, but mine was on VHS. Sceery makes a lot of good calls. Other than the Verminator tweety, Sceery calls are all I use. He makes a deer stopper call that brings coyotes in good too.
