This 3 Inch Pellet Chimney Adjustable Wall Strap from the PelletVent Pro series is a Type L Biofuel Chimney Pipe component and consists of the duralock system for a tight seal. Use to support vent pipe or tee sections. Adjusts to provide 1"- 3" clearance. Features: Type: Wall Strap. Adjustable. Collection: PelletVent Pro. Adjusts to Provide 1" - 3" Clearance. Specifications: Overall Dimensions: 3" (D) x 2" (H).