52mm or 55mm Caliper brake inserts

[HLaB]

Just been having a look at replacement caliper brake inserts, on the CRC site they are listed as either 52mm or 55mm where as other sites just list them as Campy or shimano compatible. I thought the 52mm was campy and 55mm was shimano but I guess I'm wrong; I'm thinking of getting them for the Bianchi but I'm unsure if I can easily get replacement inserts down the line or can I use any 55mm inserts, like these or are the inserts also campy/shimano specific ?

Edit I'm unsure whether this should have been posted in accessories, if so any mod feel free to move it :-)