I have an old one (not even sure of the make) that I've used alot over the years, hand held uses 22 shells and you can get different loads depending on how far you want to launch the dummys. I'm not crazy about the dummies, 1 hard floater and 1 nylon soft, but for getting a young dog started and association ( noise, something falls out of the sky) skills it's really fairly useful. I'm sure there are better ones on the market today but I'd say if you're going to train your dog or dogs it's a tool you want to have.
Kobie the wonder dog says" Hunting seasons over? Wake me up around noon"