Methods and apparatus for controlling air supplied under pressure to a patient suffering from sleep disorders such as apnoea. Methods of using the same are described. Furthermore, if the linkage becomes disconnected from the master latch assembly andor the auxiliary latch assembly, or the linkage breaks, the springs will cause the bolts of the master latch assembly and the auxiliary latch assembly to be retracted to an opened state. The contact surface of the bud may be changeable by adjustment of the adjustment ring. For that purpose, the PLAD calculates its distance to each currently valid destination at which a service is reserved, and sends a proximity notification signal to an address associated with a respective destination when its distance to the respective destination is less than a predetermined threshold radius limit acquired during the reservation process.