TWPro is HETAS Approved and is CE marked.
EN1856-1 T600 N1 W V2 L50040 G50.
EN1856-1 T200 W V2 L50040 O20.
TWPro Twin Wall Insulated Chimney parts are secured together by using a Locking Band.
Make sure that you keep a distance of 50mm from the outside of the flue to any combustible material (wood, plaster board).