GYLON BIO-PRO® seals offer a safe solution with its modified and restructured PTFE material, pre-formed and stress controlled, for all Tri-Clamp® standards. It is dimensionally stable and resists intrusion. You may notice our GYLON BIO-PRO® gaskets have printing on them so we thought it would be beneficial to explain what it meets from a certification standpoint. A specific branding ink is used to mark the sheet material (GYLON® Style 3504) from which the final products are manufactured. The branding ink complies with FDA Code of Federal Regulations Title 21, Section 175.300. GYLON BIO-PRO® has successfully passed all third-party laboratory testing (e.g. Migration testing according to (EU) No 10/2011, FDA extraction testing or biocompatibility testing according to USP VI <87> and <88>) with the branding ink being applied to the product.