The present invention provides a frame and cover assembly for use with a truck having a truck bed. A coil of electrically conductive material may be associated with the flexible carrier. The dose setting mechanism may further include a dose dial sleeve rotatably engaged with the helical thread of the inner body and a dial grip connected to the dose dial sleeve and releasably connected to the drive sleeve. A method of releasing a mask from a patient’s face includes pulling a cord away from a frame of the mask to release a latch of the mask frame from a latch receiving portion of a headgear of the mask to release the latch from the latch receiving portion. The switching circuit is responsive to the detection of radiofrequency triggering signal emitted by an extra-body remote control.