DB625 is a 6 inch by 25 feet aluminum flex liner that can be attached to an outside air adapter. Insulation and silicone are sold separately - part #s 8TC070-6X25 and SIL500 Genuine OEM...
The National Chimney DBP625KIT is a 6” x 25’ Stainless Steel Chimney Liner Kit for Wood Stoves that includes Tee, Tee Cap, 25’ Pre-Insulated Stainless Steel Liner, Top Plate, Chimney Cap.
The National Chimney DBP635BK is a 6” x 35’ Stainless Steel Chimney Liner Kit for wood inserts that includes Appliance Adapter, 35ft Pre Insulated Stainless Steel Liner, Top Plate, Chimney Cap.
Ultra Black Double Wall Stove Pipe series. 8" diameter Masonry Adapter (12” long) thimble sleeve to connect UB at thimble. Comes with flat trim ring. Genuine OEM Part