PelletVent Pro 3″ Pellet Chimney Ceiling Support Firestop Spacer This 3 Inch Pellet Chimney Ceiling Support Firestop Spacer from the PelletVent Pro series is a Type L Biofuel Chimney Pipe component and consists of the duralock system for a tight seal. Required where vent passes through ceiling. Centers Pipe to Provide Proper 1″ Clearance. Includes: Support Clamp. Features: Type: Ceiling Support Firestop Spacer. Collection: PelletVent Pro. Type L Biofuel Chimney Pipe Component. Centers Pipe to Provide Proper 1″ Clearance. Specifications: Overall Dimensions: 9″ (L) x 9″ (W) .