Before the season I was given a handful of both Zink and Flextone diaphragms to try. I was impressed with most of the calls-tonal range, ease of use, etc. and hunted w/ them for several days. By the second week of the season the calls had lost the original tension on the latex, the tape was wrinkling, and they didn't call worth a flip. I'm real anal about taking care of my diaphragms and used an original Woodhaven Copperhead (which I re-taped last year) and is at least 5 years old to call in 6 or 7 birds this year and it will probably be good next year. IMO and from feedback from several other knowledgeable callers both Zink and Flextone have serious quality control problems and you definitely don't get what you paid for in quality or longevity. I'm glad mine were gratis, but that still didn't stop me from cussing a bluestreak when they didn't perform as expected during a hunt.