Reading a Shimano pad code
The letter tells you the caliper family and the number tells you the shape. B05S fits the 2-piston road and lower-tier MTB calipers, G05A the cross-country ones, D03S the 4-piston trail calipers. The RX suffix means resin.
None of these have cooling fins. Finned pads shed heat better on very long descents, but they cost more, and for most riding the plain version is the sensible buy.
Resin is Shimano's quiet, progressive compound — easy on rotors and pleasant on the road. If you regularly descend loaded or in the wet, look at metal instead in the wider brake pads and rotors range.
