OPSMEN Electronic Ear Earbuds can help reduce continuous noise and impulse noise, improve perception and communication in noisy environments. This professional noise cancelling earplug can suppress noises higher than 82 dB with two modes of ambient sound adjustments for indoor and outdoor environments. There is 1 Lithium-Ion batteries required, and it is included. The battery life can last up to 8 hours, and it provides a low-battery reminder. The charging case is portable and does not require battery replacement. There are several different ear tip sizes that are ergonomically designed to be more comfortable for wear and a silicon retention cord is provided for you to help assure they don’t get lost. OPSMEN Electronic Ear Earbuds are suitable to wear for shooting training, law enforcement, manufacturing, construction or any high-noise environments. There is a 90 day no risk money back guarantee and limited lifetime warranty. OPSMEN will completely refund your purchase.