Vitreous pipe: 5" heavy-grade vitreous flue pipe with soot door: two lengths availableDistance from bottom of pipe to top of soot door is 25cm (on all pipes offered in drop down list) and so anything above this can be cut. *As with all vitreous pipe the bottom end narrows to a lesser diameter to enable insertion into other pieces of pipe (male is always on top). Key reason is that any condensation that trickles down inside pipe cannot escape. See here for more info on clearances above stoves: http: www. stovefittersmanual. co. uk