The WSM 40 UHF Wireless Microphone systems from AKG operate on fixed frequencies between 710.4 mHz and 734.6mHz and deliver an audio frequency response of 40Hz to 20kHz. Up to two of these non-diversity systems can be used simultaneously at the same venue.

The SR 40 non-diversity receiver has a balanced XLR microphone level output as well as a TRS line level output jack for connecting to any recording or live mixing system. The adjustable squelch and SAW noise (Surface Acoustic Wave) filters suppress unwanted radio noise. The receiver has an RF status indicator, front panel antenna jack and an optional rack mounting kit available.

The WMS 40 transmitters come in two versions: the HT 40 handheld microphone and the PT 40 bodypack for condenser mics or instrument use. The HT 40 has a built-in antenna, on/off/mute switch and AKG's Emotion Series D 880 microphone element. The PT 40 is the size of a pack of cigarettes and has both mic and line level inputs. Both of these transmitters run reliably for more than 30 hours on two AA batteries.