Sennheiser SL RACK RECEIVER DW-4- US SpeechLine Digital Wireless SL Rack Receiver DW-4-USThe SpeechLine Digital Wireless SL Rack Receiver DW 4 US from Sennheiser is an easy to integrate wireless receiver for the SpeechLine Digital Wireless System. It features an OLED display for easy setup and operation and can be used when paired with a wireless transmitter and microphone (sold separately) for applications such as lectures, meetings, and more. With secure 256 bit AES encryption, the receiver has bi directional communication, which allows