Bianchi headset by Fratelli Brivio for integrated 1" headsets.

This is a headset for Bianchi bikes from the 40s/50s, the ones that had these beautiful semi-integrated headsets.

For which type exactly, I do not know.

Appears to be NOS.

The upper cup's nickel plating is a bit yellowish and has suffered a bit from corrosion on the edges.

Bought it in Italy at L'Eroica in bope that it would fit my Umberto Dei bicycle which turned out to use a slightly different standard.