Monaural headsets with shielded cable use only with snom IP Phone 320, 360, and 370. Note: Requires PoE for optimum voice quality and noise suppression. Requires upgrade to three prong, power supply (SH-PS-GND) with grounding wire when PoE is not used. The new snom HS-MM2 monaural headset provide users with more headset stability, ease of use, comfort, and hands-free convenience in their daily communication. The snom monaural headset has one ear pad which can be worn on either ear. With the noise- canceling microphone, boom the snom headset keeps your voice crystal clear.