The TireMoni system that controls the tire pressure permanently screwed onto the valve air pressure sensors, is well known. Unfortunately, this assembly has the disadvantage that the sensors must be removed when refilling the tires. For this purpose, a small Allen key is needed to unlock the anti-theft device. Those who want to save this "Fummelarbeit" accesses this adapter which both the sensor picks up, as also offers a second valve port for replenishing the air. However, the length is quite large and the whole weighs accordingly so that the tire must be balanced in each case. In addition, you should make sure that the whole does not extend laterally beyond the edge of the rim. Therefore, the adapter is probably only with larger tires. Hence a buy rating with the appropriate restrictions.