DSR700 V2 (discontinued)Details https://www.akg.com/support/DSR700group_.html
The DSR700 V2 reference two-channel digital wireless receiver offers an ultra-wide bandwidth of up to 155MHz for reliable operation with great flexibility. It comes in a durable, 19" housing and works with all DMS700 V1 and V2 transmitters. The receiver finds interference-free channels and synchronizes the corresponding setup data to the transmitter via infrared. The environment scan converts the DSR700 V2 into a spectrum analyser. It scans the receivers entire frequency band for active radio frequencies and displays the spectrum.