The Programmable Valve Medos offers the ability to optimize the opening pressure of a shunt system before and after implantation. The condition of a shunted patient may vary throughout the treatment. When this happens in a shunted patient with a fixed pressure shunt, the system pressure stops being optimal for the patient. The programmable valve allows the surgeon, in a non-invasive way, to change the opening pressure from 30 mm to 180 mm H2O in 18 steps, eliminating the need to change the valve for the pressure. The Medos Hakim valve has 18 ranges of pressure. The defined pressure range is externally changed by a programmer. The valve is programmed in 10 seconds. After doing this, an x-ray is taken to verify that the expected pressure has been reached. Valves are supplied without any programmed specific pressure. This means that they must always be programmed before being implanted. After deciding the initial pressure that will be used with the patient, the valve will have to be programmed in its packaging, placing the four feet of the programmer head in the four blister depressions of the plastic packaging and aligning the arrows on the programmer head with the arrows of the package. Modifying the pressure does not require a review or surgery and it can be carried out at the doctor’s office. The pressure ranges are perfectly defined; there is no superposition. Precision and stability are reached by means of a system integrated by a flat metal that exercises certain pressure on a sphere placed on a circular opening. When the LCR pressure surpasses the one determined by the metal, the sphere moves up allowing the entrance of LCR through the opening. The sphere, in turn, rotates freely producing a self-cleaning process, avoiding the formation and accumulation of protein inside the valve. The definition of a new pressure must be determined considering all the patient’s clinical symptoms and the surgeon’s own experience. It is recommended that pressure variations of the valve within a 24-hour period should not exceed 40 mm of H2O.