It used on the entrance Wire rod blooming mill."A pair of compression springs + two adjustment screws" regulating the opening and closing the arm to adjust one pair of guide rollers of the mouth opening; it has a end face cam adjustment device, it can trim the opening degree of Guide Roller, on-line. This regulation is a single point symmetry adjustment. Guide roller axles adopt oil or fat to lubricate. Support arm with cooling water hole, water cooled guide roll, also water entrance in support arm. Base and the cabinet split, with bolted connections, guide and guard for the different beams, different base, while the box can be generic, which can reduce the number of spare parts