I've tried two - about fifteen years apart and returned them both. The most recent tryout was last year. It was a Leight model and I don't think it was a cheap one. I don't remember the brand from years ago, but it wasn't cheap either. I was less than impressed with these electronic gizmos. Earplugs and a good muff are far better and require no batteries or controls.

If you're shooting something that isn't very loud like a .22, the electronic wonders are probably fine.