I purchased these for a fretless neck epoxy coating project that I never got to. However I've done other projects using System Three Mirror Coat and they turned out great. These are still packaged and have never been opened or used. System Three states on their website that they have indefinite shelf life. I learned and gained the insight on how to do these epoxy fretless coatings here on Talkbass. Price includes shipping to lower 48, no international, PayPal only