A laryngeal mask tube has of a dual-airway tube, a mask with an inflatable bladder and an inflation indicator device. The chamber has a front plate and a back plate located on opposite sides of the chamber, and each of the front plate and the back plate has a first through hole and a plurality of second through hole formed therein. During testing, the signal logger is coupled to a device under testing. Terminal 50 sets the delivered WEP key itself.