This is a new wedge and stem technology ensures smooth functionality with outstanding low torque values.  New guiding system for the wedge with male composite sliding skate in order to easily achieve the 2500 cycles endurance test required by European standards.  Bayonet stuffing nut with three O-rings to guarantee the tightness throughout the stem.  Patented three locking tab for bayonet system to avoid self-dismantling, leakage and blow up risk.