The size of the dishes to be intended for dogs with a chest circumference of 30-60 cm. My dog is just below the 60 cm chest circumference, weighs 13 kg and has a height of about 40 cm. This dishes and especially the thin ring for hooking the Restraint Strap would strong braking, in which the dog is thrown forward not survive for sure. Only when driving with heavy train I would have been afraid that he bends apart.
The hook of the Restraint Strap however looks very stable, although the belt is not wider than that of Geschriss, but still looks solid.
My conclusion: For small, lightweight dog certainly a good solution, but not for dogs that are at the border to the next size rather. I would estimate up to 50cm chest it would be ok.