Why this ducting earns its place
This Combisteel converter bridges the gap between square extraction risers and round ductwork, common in kitchen extraction systems where you run a main square trunk and branch off to fans or canopies with round fittings. It takes a 400 × 400 mm square inlet and steps it down to a 250 mm round outlet, making it a natural fit for mid-sized installations where space is efficient and airflow is steady.
The converter is built as a robust transition piece, 400 × 400 × 280 mm in profile, and sits flat against the canopy or wall—no wobble, no rattle. Whether you're assembling a new extraction system or retrofitting an older one with modern components, this adapter lets you join square and round ductwork cleanly without improvisation or manual bending. It's the kind of unglamorous component that quietly handles its job—proper airflow transition, no turbulence, no leaks.
Installation is straightforward: clamp or screw the converter between your square duct section and your 250 mm round ductwork, seal the joints with foil tape or sealant, and you're done. It's a one-piece adapter, so there's no assembly required. Contractors and kitchen fitters rely on adapters like this to keep systems airtight and efficient.
