4 Pistons PM Front and Rear - 203 mm discs.The M4 is a new 4 -piston Clarks braking system.Our most powerful production brake produced to date, the M4 is light with a thin design and 4 x16 mm pistons for caliper, each of which offers a fluid braking force, powerful and modulated on the discs.Perfect for all driving conditions.Suitable for e-bikes, the M4 is the ideal braking system for the most demanding environments in which perfect braking is required.Disc diameter:203mm.Mount:front e rear.