Sound is muddled, in fact and there are no batteries to fussle with. If you view FSL's other products, they are all moderately priced. These are by far, better than what you're offered at shooting galleries and you don't have to spend hours, then days later, scratching your head and wondering what's up there.
The FSL Gunblock earmuffs list for $29.99. But, they currently list for $14.99. They are certainly worth the buy.
Vital Link: Amazon