Selkirk 3 in. Type B Adjustable Wall Thimble

This 3 in. Type B Adjustable 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.|Durable galvanized steel outer pipe|Internal spacing bends provide uniform insulating air space between the pipe walls|Die-formed ends provide uniform sizing for strong, easy-to-connect joints|Lock tab feature helps installers to engage the tab without sheet metal screws|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 NFPA 54 and NFPA 211