Valve for air chambers comprising a fixed body (11) and a mobile selector body (12), wherein the mobile selector body (12) is disposed coaxially in the fixed body (11) by a thread and moveable between a first position of use, associated during to a first outlet (15), and a second position of use, associated during use to a second outlet (16); a mechanical stop system is provided, configured to prevent the axial dis-insertion of the mobile selector body (12) and the fixed body (11), and a mechanical end-of-travel system is provided, configured to define an end-of-travel of the rotation screwing of the mobile selector body (12) and the fixed body (11).