25.2. For vehicles of categories M, N1, N2 with a maximum mass not exceeding 8 t, O1 and O2, the ground clearance with respect to the underside of the protective device, even when the vehicle is unladen, shall not exceed 550 mm over its entire width and shall be such that the height above the ground of the points of application of the test forces to the RUP does not exceed 600 mm. a0c0