This model rear derailleur appears in the 1999 and 2000 Campagnolo Catalogs. The outer parallelogram plate is chrome plated aluminum with these raised letters: Campagnolo MIRAGE 9 SPEED. The 1999 Catalog lists this as Model RD09-MI3, the 2000 Catalog as RD99-M309. The replacement parts appear to be the same. The outer medium length pulley cage plate is stamped aluminum while the inner is stamped steel.

Campagnolo used a narrower pulley cage and pulleys to work with a 9 speed chain on these derailleurs. Previous models were designed for wider 8 speed chains. I'm running an SRAM 6-7-8 speed chain and an 8 speed Shimano cassette with no problems.

These were designed to work with Campagnolo Ergo Power 9 speed brake/shift levers (brifters). I'm using Campagnolo Doppler Retrofriction down tube shifters and they friction shift as smoothly as any index system thanks to the upper puller with lateral float which allows the chain to self center on the sprocket.

I've listed a matching braze-on triple front derailleur under Campagnolo Mirage-T FD-11SM13