I've searched lots of stores for good Pop-Top jars only to find poorly made glass with loose fitting pop-tops that aren't airtight. That all stopped when 420science sent me one of these as a free gift and I discovered they sell the highest quality Pop-Top jars I've ever used. Stashed some product Inside one of these without a Boveda pack by mistake for about 90 days and it was still fresh when I opened it up again! Now I only use 420 jars because they're so well made and designed. Nothing else comes close.