Espagnolette for a locking system of a device for closing an opening of a construction, this espagnolette: - including: - a housing; - a follower, at least rotatably mounted inside the housing along an axis of rotation as well as between an unlocked position and a locked position, and comprising a toothing as well as an opening for receiving a transmission square rod; - a rod, movable in translation relative to the housing in a direction of translation, and including a rack engaged with the toothing of the follower; - accommodation means for accommodating the transmission square rod inside the opening of the follower, with a transverse clearance in a transverse direction relative to the axis of rotation of the follower; - mounting means for mounting the follower inside the housing, with a longitudinal clearance in a direction parallel to the direction of translation of the rod, these mounting means including, on the one hand, two hubs, which the follower includes laterally and on both sides and, on the other hand, two accommodations, which the housing includes on both sides, which each extend along an axis parallel to the direction of translation of the rod, and inside which said hubs extend; - being configured so that, when the follower is in the locked position, the transverse clearance and the longitudinal clearance extend in the same direction, so to permit a displacement in translation of the follower relative to the housing; - wherein, on the one hand, the two hubs each adopt a circular shape and, on the other hand, the two accommodations each adopt an oblong shape. - including: - a housing; - a follower, at least rotatably mounted inside the housing along an axis of rotation as well as between an unlocked position and a locked position, and comprising a toothing as well as an opening for receiving a transmission square rod; - a rod, movable in translation relative to the housing in a direction of translation, and including a rack engaged with the toothing of the follower; - accommodation means for accommodating the transmission square rod inside the opening of the follower, with a transverse clearance in a transverse direction relative to the axis of rotation of the follower; - mounting means for mounting the follower inside the housing, with a longitudinal clearance in a direction parallel to the direction of translation of the rod, these mounting means including, on the one hand, two hubs, which the follower includes laterally and on both sides and, on the other hand, two accommodations, which the housing includes on both sides, which each extend along an axis parallel to the direction of translation of the rod, and inside which said hubs extend; - a housing; - a follower, at least rotatably mounted inside the housing along an axis of rotation as well as between an unlocked position and a locked position, and comprising a toothing as well as an opening for receiving a transmission square rod; - a rod, movable in translation relative to the housing in a direction of translation, and including a rack engaged with the toothing of the follower; - accommodation means for accommodating the transmission square rod inside the opening of the follower, with a transverse clearance in a transverse direction relative to the axis of rotation of the follower; - mounting means for mounting the follower inside the housing, with a longitudinal clearance in a direction parallel to the direction of translation of the rod, these mounting means including, on the one hand, two hubs, which the follower includes laterally and on both sides and, on the other hand, two accommodations, which the housing includes on both sides, which each extend along an axis parallel to the direction of translation of the rod, and inside which said hubs extend; - being configured so that, when the follower is in the locked position, the transverse clearance and the longitudinal clearance extend in the same direction, so to permit a displacement in translation of the follower relative to the housing; - wherein, on the one hand, the two hubs each adopt a circular shape and, on the other hand, the two accommodations each adopt an oblong shape.