Yes this is a kit to [partially] rebuild those 4 piston goldline Brembo calipers found on just about all Ducatis, both the 40mm mount and the 65mm mount 30/34 type.
Each kit is for 1 caliper and contains; 2 x 30mm pistons & seals plus, 2 x 34mm pistons & seals along with a pouch of Brembo installation grease. This kit is lacking the small oring that goes between the caliper half, as well as the secondary stepped piston seals. Although these are genuine Brembo items, they are not a readily available catalog Brembo part number. I don't know if I will be able to get more from Brembo..... So you have 2 choices if your 30/34 calipers are going bad....... Buy new ones, or, buy this 'kit' and replace what you can.
NOTE: This kit is specifically for the racing billet 30/34 calipers and are as supplied to Brembo sponsored racers that used those calipers. The pistons may or may not fit your OE calipers but the seals do. Regardless, these are the only option for getting seals on any 30/34 Brembo caliper.