PurePak™ PTFE/Silicone seals are packed in glass jars to maintain purity up to the point of use; Molded polyethylene SepCap™ is suitable for short-term storage or where repeated access to the vial is required; SepCap is for short-term storage. Do not use SepCap at elevated temperatures. Order Info. Septa and crimp seals also sold separately.