I took a punt on this one....and it paid off.!!! My original JBL diaphragm had warped and was binding on the core. After removal and cleaning the voice coil ring as per a youtube video the new one went in a treat. Back cover replaced and the horn put back into the main sound system array. amps fired up you just cant tell the difference. Even a direct A/B test again a genuine vs. this cheaper replacement you couldn't perceive a variation. As for longevity in service, only time will tell, but the build quality suggests it will last every bit as long as the original, which in my case was 33 years!!!!