When a power supply switch is turned on and an RF signal and an LO signal are input to a bipolar transistor, a mixed signal of both signals is output as an IF signal. The multiplexing device is coupled to two system ports and two device ports. The metal-filled polymer extends through the truncated parabellum and forms a tip on the projectile. The holes allow the water to flow into the piping system and discourage any debris from flowing into the piping system and clogging it. In particular, the bobbin of the bobbin-coil assembly is adapted to resist induced eddy currents thereby allowing a fewer number of coils to be used which in turn reduces undesirable interaction with the musical instrument pickup. The improvements involve optimizing the shape of the spacer assembly body member and providing an efficient MDI nozzle assembly to allow maximal evaporation of the propellant before the propellant droplets impact the walls of the body member while providing a compact volume for directing the output of an MDI canister or a nebulizer into the gas stream.