That simple little green, snake-like, sheathed sponge with the pen clip that connects to the string that connects to the plastic soundhole cover. So primitive, and yet so effective and essential. It may be only $11.95 but it can help save your instruments’ lives. Dryness is, of course, a mandolin's worst enemy and the Dampit, in its unpretentious way, when properly loaded (just like ourselves, most afternoons) is the difference between the buzzy and the brilliant, the shriveled and the secure, the moistened fortification and the fissure.