I put a Kamui Black Medium on my Revo 12.4 and it was too hard. So I tried the Kamui Athlete Medium and it is just right.
The Kamui
Athlete medium tip you preferred for your Revo over the Kamui
Black medium tip is supposed to be designed for carbon fiber shafts. It makes sense the Athlete medium was not as hard since the Athlete has soft layers on top and hard layers on the bottom. From PoolDawg's description of the Kamui Athlete 8-layered pigskin tip below
Kamui has stepped up the game with the first tip designed specifically for use with carbon fiber shafts. The Kamui Athlete tip is made to enhance the performance of your carbon fiber shaft through a perfect balance of elasticity and rigidity, giving you the control you crave. Constructed with soft layers on the top and hard layers on the bottom, the Athlete complements the characteristics of your carbon fiber shaft, maximizing its responsiveness and feel. You'll experience a cue ball that reacts exactly how you intend, revolutionizing your game
Hardness scores: none given
From PoolDawg's description of 8-layered laminated Kamui Black:
Kamui Black Tips are made from high quality, specially selected pigskin. With each Kamui tip, the leather is tanned by a special moisture proof tanning, giving the Kamui Black the black color and making it "humidity resistant". Kamui Japan found the way to apply this process without interfering with the porosity, adding more elasticity to the tip and protecting the tip from the environment
Hardness scores: 67.5-Super Soft, 72.3-Soft, 78.7-Med and 84.8-Hard