One set of 4 pads. For carbon fiber rims.
Black prince is a special compound that is offering a better modulation than yellow king pads. The low profile version is designed for super wide rims like Zipp 404 or Enve carbon rims.
For alloy rims. Special compound for alloy rims.
One set of 4 Swissstop GHP RXplus pads. Compatible with Shimano XT/XTR cantilever brakes, and Ciamillo cantilever brakes: Ciamillo GX.
About 28g per set of 4. Very efficient on aluminim rims. Should not be used on carbon rims.