In a pair of lower hooks for a three-point coupling, each hook (12a, 12b) comprises a body (15) with a right-hand side and a left-hand side with respect to a longitudinal median plane (M). A crook portion (16) protrudes from a case portion (17) in which are housed actuating mechanisms for a closure means (19). The case portion (17) defines with one of its walls a first side (14a, 14b) and is closed by a plate (18) which defines a second side (13a, 13b). The first and second sides of the pair of lower hooks are respectively disposed symmetrically with respect to the longitudinal median plane (M), in such a way that the first side (14a) of one hook (12a) is for example on its right-hand side and the first side (14b) of the other hook (12b) is instead on its left-hand side. The two hooks are therefore substantially mirror images of each other with regard to the case portion (17) and the closure plate (18). In this way a right-hand hook and a left-hand hook of the pair of hooks are defined, and the pair of hooks withstands the stresses to an optimum degree when it is mounted on a three-point coupling of an agricultural vehicle.
