Thanks for bringing your question to Tundra Restaurant Supply.
This Libbey 97085 County Fair 16 1/2 oz Drinking Jar may look like a mason jar, but the design is purely aesthetic. There is not a lid that fits this jar/glass, and a regular mason jar will most likely not work/fit as a sealed and secure cover.
Here at Tundra Restaurant Supply, we are happy to help answer your questions about our products. The Libbey 97085 County Fair jar comes in a case of 12 and weighs 11.5 lbs. This breaks down to just under one pound per glass. This is very comparable to many mason jars which typically weigh between 10 and 14 pounds for a case of 12. Thanks for your question and let us know if we can be of further assistance.