Gamma Seal Lids are a two piece sealing system that allows you to transform a standard bucket or pail into an easy to use air tight container. Gamma Lids fit most 3 gallon (12L), 3.5 (14 L) and 5 gallon (19 or 20L) plastic pails and buckets. Snap the adapter ring to any 12" diameter bucket, then spin on the heavy duty gasketed lid. Re-seals Your Bucket. Easy Opening Lid. Spin off to open, Spin on to close. Food Grade Plastic, BPA Free. High-density polyethylene construction.