90° connector between rectangular duct 204x60 and round duct D125

The 620SK12,5KP is a 90° duct adapter that connects a 204×60 mm rectangular (flat) ventilation duct to a Ø125 mm round duct or pipe. It is the standard transition piece used wherever a flat duct run needs to switch to a round spigot — for example when connecting to a fan, a heat-recovery unit, a silencer, or an existing round duct system.

Made from durable white plastic, the round outlet has a plain spigot end sized for a direct push-fit into a Ø125 mm round duct of the same diameter; the rectangular end mates with standard 204×60 mm flat duct fittings. For a fully airtight joint we recommend sealing the connection with aluminium duct tape.