These 20mm Green Flip-Off Aluminum Vial Seals deliver pharmaceutical-grade closure integrity for serum vials in sterile compounding, laboratory, and research environments. Each seal features a lacquered aluminum shell with an attached plastic flip-off button that provides convenient access while maintaining tamper-evident security. Engineered for 20mm crimp-finish vials with 13mm openings, they ensure reliable container closure and contamination prevention. The pack of 100 seals meets stringent standards for pharmaceutical applications where sterility and product protection are non-negotiable. Ideal for compounding pharmacies, clinical laboratories, and research facilities requiring dependable vial closure solutions.