The X30i Earplug features a valve that opens and closes with a simple toggle switch. This lets you instantly transition between hearing and protecting at the same time or hearing protection only. The X30i Earplug product is designed to provide the wearer with hearing protection against two types of noise: continuous noise (Closed mode) and impulse noise (Open mode). The mode is selected by operating the toggle switch while the product is in the ear. The X30i Earplug features multiple tip sizes and styles to choose from. This lets you fully customize what feels best for you while protecting your hearing. Ideal for extreme noise environments such as air travel, concerts, auto racing, stadium events, shooting, machine shops, farming, roadbuilding, and construction; any situation where health and safety require the use of hearing protection i.e. where noise levels are above the safe limit of 85 dB.