Small green translucent plastic earplug case with a screw-top lid and a metal bead chain for attachment to other survival or field gear. The case contains a pair of foam or rubber earplugs (visible through the translucent plastic). The bead chain allowed the case to be clipped to a uniform buttonhole, flight suit zipper, or the interior of a personal survival kit.
Such ear protection was standard issue for aircrew and artillery personnel during the Second World War and early Cold War, reducing hearing damage from aircraft engines and gunfire. This example was found inside a yellow canvas survival kit (2020.549.001).