Asynchronous mechanism with forward pivot, 15° inclination of the backrest and 9° inclination (+4° ÷ -5°) of the seat. Thanks to the activation of a clutch and a gear, the backrest and the seat can be adjusted separately. When the gear with anti-shock system is left open, the backrest takes on the function of permanent contact and can then be locked in any of the 6 positions. The seat can be locked in any position available through the seat clutch. The tension of the backrest can be adjusted according to the user’s weight by turning the knob located underneath the mechanism.