You paid a lot for your Bose A20 aviation headset. Our Bose A20 Hygiene Kit can help maximize your return on investment. Inside the kit, you'll find a brand-new head pad, a replacement mic muff, and a fresh set of ear seals - all of which are identical to your A20's original parts. Simply replace the old with the new, and you'll be pleasantly surprised at how youthful your trusty earphones seem. By far the wisest purchase an A20 aviator can make.