Lee Valley Tools sells a virtually identical product called Zem Hearing Protectors. I was sceptical but decided to give them a try. IMHO, a waste of money. They didn't sit comfortably on my head and were too light to stay on while doing any sort of physical exertion (chain saw, circular saw etc.) In addition, I flatly don't believe the NRR rating, which for the Zem anyway is a claimed 26dB. They just sit on your ear and don't provide any sort of real seal.
I use custom moulded in-ear plugs which I find really good unless I'm on the range and there are a bunch of other shooters on the line.
Hickock45 ("Your internet shooting channel") uses Howard Leight QB2HYG banded plugs ( Link here
)and seems to find them satisfactory. Hard to argue with a guy who shoots as much as he does! I use them (and the very similar QB1HYG) for power tools and would use them with guns in a pinch, but I'd recommend in-ear plugs, like the Howard Leight "Quiet" plugs, ( Link here
) or muffs if you really want protection.