Marker actually uses two different piston systems. The "Comshock" piston is in the toe and is a fluid that stiffens when agitated. It is designed to dampen shock vibrations and provide more holding power in the toe for brief shock loads and vibration (technically described as non-newtonian fluids
The Piston Control that attaches to the ski and binding interface, known as iPT, PCOS and Piston Control Turbo are designed to dampen ski ossilation
Originally Posted by marker
Piston Control allows skiers to load and bend the ski in a bigger, deeper more bowed-like radius throughout the turn. During counter-flex, when the ski is unloaded or unweighted, the Piston Control Interface manages the ski’s rebound and prepares it for the next turn. Skiers initiate quicker, cleaner and smoother turns. The feeling is simply sensational.
(and I'm merging these two similar threads).