Excel Insulated, Adjustable Stud Support, Fits All Sizes

Allows you to install a round or square support (ERDS, ES, and ESS) without the need for wood framing. The maximum chimney support capability is 30 feet. The maximum center-to-center joist spacing is 24".
Construction:
Flue: .016" stainless steel
Casing: .016" stainless steel
Seam: Interior and exterior seams are continuous seam welded
Insulation: Thermoplus continuous blanket
Wall thickness: 1