From manufacturer's official website:

The Record™ rear derailleur is the symbol of the Record™ groupset and communicates an unarrestable competitive charge thanks to the dominant presence of carbon fibre. Every particular has been designed down to the smallest detail to obtain the maximum effectiveness. The Record™ rear derailleur ensures rapidity and precision in every situation.

Available with a short or medium cage, to interface perfectly with classic and compact cranksets. Composite outer plate - Titanium hanger and pivot bolt - composite outer cage

Short cage: Upper to lower pulley-axle: 55 mm
Nominal weight: 184 g.

Medium cage: Upper to lower pulley-axle 72,5 mm
Nominal weight: 193 g.

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