Abstract: The invention relates to a clasp for bracelets with a length adjustment device, wherein the adjustment device is devoid of a locking mechanism for blocking the length adjustment and/or of an activation member for unblocking a locking mechanism in order to allow the length adjustment in at least one direction of the length of the bracelet. The clasp enables a user to finely adjust the useful length of the bracelet by thrust or traction on the bracelet strand.

Abstract: A device for adjusting the length of a bracelet comprises a frame carrying an adjusting element capable of sliding in the longitudinal direction of the bracelet, and an element for fastening the bracelet, mechanically connected to the frame. The device comprises a jaw which can move in response to an action by a user on a control element, and is designed to lock the adjusting element or leave it free, to define several adjustment positions. The device has an automatic conversion mechanism designed to convert an action on the control element into a sliding movement by one increment of the adjusting element, to adjust the length of the bracelet.