2020/03/02 · National Scientific Aluminum Crimp Seals with Prefitted Septa for 8 mm Crimp Top Vials • Provide leak-resistant seal • Clear PTFE/Red rubber septa • Catalog no. 845-49726 uses Red PTFE/White Silcone/Red PTFE septa and is used for aggressive solvents • Catalog no. 845-49711 is a One Piece Snap-