Masterbach dispenser and / or additive specially built to feed the injection machines of clients that require a maximum precision in the dosage, guaranteeing a saving of material thanks to the powerful microprocessor of last generation that controls and ensures the exact amount of additive and / The masterbach; Since the dosage remains constant even when a cycle change of the same injector is present. It has the capacity to store and memorize up to 200 recipes, it also has a light level sensor that sends a signal if there is no material available. Suitable for dosing any granulometry and micropellet.