Quality Crystals® from Fil-Tech, QI8010 and QI8008! Fil-Tech supplies 6MHz, 5MHz and 4.4MHz piezo sensor crystals coated in Gold, Silver, Stress Relieving Alloy®, Longer Life Gold®, and Advanced Adhesion Alloy®. Fil-Tech offers replacement crystals comparable with INFICON, Maxtek, Satisloh, Balzers, Umicore, Ulvac, Sloan, Intellemetrics, Phelps and Veeco crystals. Learn more about our Quality Crystals from our Quality Crystals Technical Bulletins 1-15.