This is a Sachs-Huret New Success ARIS discreetly decorated with the word 'approved' and Galli's rooster symbol ('gallo' is the Italian for 'rooster'). By the late 1980s Galli needed a decent indexing derailleur for its better groupsets, and did not have the resources to design one of its own. Instead it adopted Sachs-Huret's model of the moment.
The derailleur itself is quite a classy piece of work. It’s a proper slant parallelogram design with two sprung pivots. The angular styling and the placing of the adjustment screws make for an individual look, and it has a spring loaded ‘cable saver’ built into the adjustable cable outer stop. It is more Shimano 600 quality than Shimano Dura-Ace, but it is a competent, composed design nonetheless.
ARIS stands for Advanced Rider Index System, Sachs-Huret’s answer to Shimano’s SIS. ARIS worked reasonably well, but lacked the degree of attention to chains and freewheel cogs that set Shimano’s system apart.
This example is the short pulley cage version.