The clamp mounting bracket accessories GN 873 greatly increases the mounting possibilities and, with that, the field of applications for pneumatic fastening clamps is vastly increased. The abutting shoulder can be used for precise positioning of the pneumatic fastening clamps thus allowing a problem free exchange of the latter. The use of the two guide bushings ensures an exact and stable installation of the clamp mounting bracket accessories as well as the pneumatic fastening clamp. Other clamp mounting bracket accessories for the sizes d1 = 40 (piston Ø 20) and d1 = 50 (piston Ø 40) are shown under the tube clamp connector range. Guide bushings are included.