Asynchronous mechanism with forward pivot, 15° inclination of the backrest and 9° inclination (+4° ÷ -5°) of the seat. Through the activation of two separate groups of clutches, the backrest and the seat can move independently from one another. When the clutch is left open, the backrest takes on the function of permanent contact and can then be locked in any position 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.