Shimano RD-2400 short cage rear mech. This is the replacement for the 2300 series rear mechs. It is an 8 speed mech and is compatible with all shimano 8 speed shifters.
The rear cage has a light weight resin inner plate and the stone finish on it adds a nice touch.
The cage appears quite long almost medium cage in length so these are the confirmed specs.
Rear max large sprocket size 32T
Rear min large sprocket size 25T
Rear max small sprocket size 13T
Rear min small sprocket size 11T
Front chinaring tooth difference = 16T
The short cage mech is designed to work with the double chainset. If you are running a triple chainset you will need the medium cage version.