How to measure piston size:
e.g. 30x32 = 30mm in diameter; 32mm in height*
All seal and boot dimensions are determined by the piston diameter.
*Two common heights: 30 and 32mm
Why RB Stainless Steel Piston (vs. Aluminum):
1. Mush lower heat transmittal, only about 10% of aluminum = Less brake fluid replacement.
2. Better dimensional stability (Lower heat expansion rate) = Better rigidity in brake torque transmittal.
3. Detail machining & thin wall cut with chrome plate on surface.