Optifleks Flier Earplugs Medium 1PrDuring a flight, pressure inside the passenger cabin fluctuates and if you are wearing earplugs the static pressure between your ear drum and earplug can cause pressure on your eardrum and can cause pain. Otifleks Flier is designed with a pressure equalizing micro filter which slowly equalizes pressure on both sides of the earplug and prevents pain caused by pressure changes. Otifleks' Micro Filter is designed to offer maximum attenuation while still