This 3 in. adjustable type B wall thimble boasts a long list of convenience features, including a durable galvanized-steel outer pipe, die-formed ends and convenient lock tabs. This wall thimble is designed for use on approved gas appliances in residential, light-commercial and industrial applications.
- Wall thimble adjusts from 4-1/8 Inch to 7 Inch to fit the thickness of the wall 
- When installed according to manufacturer specifications, the wall thimble provides the required 1 inch air space to combustibles 
- Tested and listed per UL-441 for installation as type "B" and B-W gas vents to be installed in single and multi-story buildings 
- Limited lifetime warranty 
- Designed for use on approved gas appliances in residential, light-commercial and industrial applications 
- Tested and listed per UL 441 for installation in single- and multi-story buildings in accordance with national fire protection association standards nape 54 and nape 211 
- Inner liner is aluminum 
- Check appliance installation instructions for details 
- Industry best warranty contact Selkirk for details