Self adhesive windsaver valves for both diatonic and chromatic harmonicas, These consist of a first layer of compressed 100% polyester with a second layer of Mylar. The Polyester will not absorb moisture and eliminates sticking valves. They are easy to install, peel and stick and stay in place. The self adhesive will not dry out and these windsavers will not fall off. You can play your harmonica immediately after installing these since there is no drying time needed. They have served me well for years without any issues. Each unit is for 12 windsavers plus a couple extras for practice assembling, instruction sheet, and free USA shipping. International shipping is on hold for now due to Covid-19.