Bath Fan Outlet To 4 in Duct Adapter
A transition that bolts over the flat oval/rectangular side-discharge outlet of an old bathroom exhaust fan housing and converts it to a plain 4 in round duct collar, so a modern flex duct clamps straight on. The 150 x 94 mm mounting flange carries a 110 x 56 mm port opening, four 4.5 mm M4/#8 screw holes at ±64 x ±34 mm plus two 14 mm adjustment slots, and the collar is Ø100.5 mm x 22 mm tall with a 45° retaining bead; overall height 70 mm.
bathroom bath-fan ductwork adapter