The reed material is 10 mil mylar, the wedge material is 3/16-inch-thick rubberized cork. Both of these are made here in the usa and are of the finest quality. The reeds are cut extra-long so they will fit a wide variety of calls. Use the existing reed you have as a template and cut them to fit. The cork wedges are also cut extra-large so you can fit them to your call, Fit the reed to your call then moisten the cork in your mouth and slide into place, use a straight edge razor blade to trim to size. If your not sure look it up on you tube. Thank you for your business, Kel