I think this is a later version of Galli Criterium.

In terms of the variables that seem to define Galli models, this example has:

• an Allen-key hanger bolt,
• a b-knuckle with a small reinforcing 'gusset' under the cable outer stop,
• an outer parallelogram plate with a rounded area of 'small dots' around the logo, and a high-mounted cable clamp arm, giving a high actuation ratio,
• a curvaceous pulley cage,
• Simplex pulley wheels,
• an hex-head cable clamp bolt.

• Derailleur brands: Galli
• Country: Italy
• Date of introduction: 1980?
• Date of this example: unknown
• Model no.: unknown
• Weight: 193g
• Maximum cog: 26 teeth (Sutherland’s 4th edition)
• Total capacity: 20 teeth (Sutherland’s 4th edition)
• Pulley centre to centre: 45mm
• Index compatibility: friction
• Chain width: 3/32”
• Logic: top normal
• B pivot: unsprung
• P pivot: sprung
• Materials: aluminum

Ref. 247