O-ring gaskets that fit 5 gallon size Gamma Seal brand, Twister Seal brand, and Poly Farm brand lids (the 5 gallon size lids are the ones used on most buckets from 3.5 to 7 gallons). Our O-rings have out-performed the factory O-rings in our in-house leak testing. The O-rings are made with FDA compliant material (translates in casual language to 'food grade'). We pre-lubricate our O-rings with an FDA compliant ('food grade') silicone lubricant for enhanced life and sealing performance. Upgrade your twist-on lids, breathe new life into those older Gamma Seals, or simply pack away a few spares with your next preparedness project. Seal it better with these Poly Farm replacement O-rings!