Aluminum seals are available in standard center hole and pressure release versions Use magnetic tinplate seals with magnetic transport autosamplers Shop Aijiren Techbrand™ 20mm Aijiren Techbrand™ 20mm Crimp Seal, Gold, Magnetic Cap, 8mm Center hole, assembled septum Silicone/PTFE white/blue,1.5mm thickness,55° shore A Aijiren Techbrand™ 20mm Crimp Seal