DuraBlack 8″ Snap-Lock Adapter with Trim Snaps into the ceiling support box or finishing collar and extends down to fit into stovepipe for a drip-free connection to a DuraTech, DuraPlus, DuraPlus HTC, or DuraLiner Chimney system. Provides a strong mechanical connection. Features: Type: Snap-Lock Adapter. Comes Standard with Trim. Built to DuraVent’s High Standards. Provides a Strong Mechanical Connection. Specifications: Overall Dimensions: 11″ (W) x 4.25″ (H). Inner Diameter: 8″.