From the manufacturer's official website:

The new Veloce™ QS™ front derailleur offers snappier faster shifting thanks to the interface with Ergopower™ QS™ controls and the greater length of the outer parallelogram link.

It is compatible with Ergopower™ Flat Bar controls and is available in two versions, standard and compact crankset (CT).

For double standard crankset: capacity 15 – max. chainring 54 - min. chainring 39.
Nominal weight: 93 g.

For CT™ compact crankset: capacity 16 – capacity 16 – max. chainring 50 - min. chainring 34.
Nominal weight: 100 g.

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