BLX Wireless Systems The ideal entry-level wireless microphone system for small venues, BLX offers professional quality sound with simple setup and an intuitive interface. Precision-built and available in a variety of configurations, it’s the most accessible way to own the stage. Includes BLX4R rack mount receiver, BLX1 bodypack transmitter, SM35 headset microphone, power supply, clothing clip, windscreens, rack mount hardware, and user guide.