A belt comprising: - a strap defining an inner face, intended to face a user's body, and an outer face, opposite the inner face; and - a closure device capable of fastening a first end part of the strap to a second end part of the strap, the closure device being movable between a tightened position, wherein the first end part of the strap is secured to the second end part, and an adjustment position, wherein the first end part can slide along the second end part, the closure device being arranged to guide a free end of the first end part of the strap against the inner face of the strap when the first end part is inserted into the closure device in the adjustment position so that, in the tightened position, the outer face of the free end of the first end part of the strap extending against the inner face of the second end part of the strap; the closure device defining an outlet passage, the outlet passage being open on the inner face side and closed on the outer face side when the closure device is in the adjustment position; the closure device comprising a support and a cover rotatable relative to the support between the adjustment position and the tightened position; the belt being characterised in that the output passage is defined between the support and the cover, the outlet passage being delimited on the inside by an external face of a first lateral edge of the support and on the outside by a hinge. - a strap defining an inner face, intended to face a user's body, and an outer face, opposite the inner face; and - a closure device capable of fastening a first end part of the strap to a second end part of the strap, the closure device being movable between a tightened position, wherein the first end part of the strap is secured to the second end part, and an adjustment position, wherein the first end part can slide along the second end part, the closure device being arranged to guide a free end of the first end part of the strap against the inner face of the strap when the first end part is inserted into the closure device in the adjustment position so that, in the tightened position, the outer face of the free end of the first end part of the strap extending against the inner face of the second end part of the strap; the closure device defining an outlet passage, the outlet passage being open on the inner face side and closed on the outer face side when the closure device is in the adjustment position; the closure device comprising a support and a cover rotatable relative to the support between the adjustment position and the tightened position; the belt being characterised in that the output passage is the closure device being arranged to guide a free end of the first end part of the strap against the inner face of the strap when the first end part is inserted into the closure device in the adjustment position so that, in the tightened position, the outer face of the free end of the first end part of the strap extending against the inner face of the second end part of the strap; the closure device defining an outlet passage, the outlet passage being open on the inner face side and closed on the outer face side when the closure device is in the adjustment position; the closure device comprising a support and a cover rotatable relative to the support between the adjustment position and the tightened position; the belt being characterised in that the output passage is