From the manufacturer's official website:

The 2007 Veloce™ Rear Derailleur is also available with the stupendous new Infinite™ finish, coordinated with the other components in the series.

Short cage: Upper to lower pulley-axle: 55 mm.
Nominal weight: 250 g.

Medium cage: Upper to lower pulley-axle: 72,5 mm.
Nominal weight: 259 g.

For more information, please visit this product's webpage.