Mason Jar Straw Lids Set of 6 (Regular, Black) Metal, one piece lids which fit any regular/standard mouth mason jars. Standard 3/8'' (9mm) straw hole size mouth with screw top, BPA free, made of metal material, with rubber seal. Metal lids look amazing are much better quality and have much longer longevity and life span than plastic Mason jar lids. Unlike two pieces canning jar lids, these are a single piece lid for convenient refill. Perfect for holidays, parties, dcor, and all occasions and can be used in the home, kitchen, office, or garage. Easily converts standard mason jars to drinking glasses, including nearly all sizes and manufacturers jars, other than wide mouth jars.