Earplanes™ exclusive CeramX™ filter adjusts air pressure on the eardrum -- automatically. EarPlanes is a pressure-compensating earplug system which works with the body's own internal mechanism to allow air entering the ear to naturally adjust to the changing rate of air pressure on the eardrum. Especially nice for those with sensitive ears or a cold or allergy. Tested by the U.S. Navy. Contains two plugs, good for two flight segments (two take-offs and landings) and a handy case. Two sizes: adult (12 years old and over) and child.