Selkirk 187704 Wall Thimble

Adjusts 10cm – 18cm to fit wall thickness. When installed according to manufacturer specifications, the wall thimble provides the required 2.5cm 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. 10cm 4RV-WT Wall Thimble. Adjusts 10cm – 18cm to fit wall thickness. When installed according to manufacturer specifications, the wall thimble provides the required 2.5cm 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.