A tandem mass spectrometer and method for calibrating a tandem mass spectrometer. The insulative body comprises a plurality of first terminals, and the base comprises a plurality of second terminals. The removing system is configured to remove, from signals created from the binaural microphone system, components corresponding to sound of a user’s voice sensed at the at least one third transducer. The inlet port is in the inner wall of the swirl chamber adjacent to the first end of the swirl chamber and provides fluid communication between a region exterior to the de-agglomerator and the swirl chamber. The invention also relates to kits for treatment andor prevention of foot ulcers, comprising an effective amount of Treprostinil or its derivative, or a pharmaceutically acceptable salt thereof. This may allow at least a portion of the frame to be exposed and visible when the table is being used.