1. 
   Glass-Seal
   3-tab self-sealing fiberglass shingles with a traditional square-tab design. A thick layer of weathering-grade asphalt gives them extra waterproofing protection. They are U.L. Class A fire rated and backed by a 20-year limited warranty. Algae-resistant granules optional.
   Found op http://www.rookinspections.com/glossary/glossaryg.shtml
   
   
2. 
   Glass-to-metal seal
   Glass-to-metal seals are a very important element of the construction of vacuum tubes, electric discharge tubes, incandescent light bulbs, glass encapsulated semiconductor diodes, reed switches, pressure tight glass windows in metal cases, and metal or ceramic packages of electronic components. Pro...
   Found op http://en.wikipedia.org/wiki/Glass-to-metal_seal
   
   

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