Shure's GLXD14/PGA31 Digital Headset Wireless System delivers stunning audio clarity, incredible ease of use, and major bang for the buck. GLX-D systems boast Shure's LINKFREQ automatic frequency management, which identifies the best open channels automatically, as well as bi-directional communication that lets your transmitter automatically link to your receiver and follow any frequency changes. If there's interference, both automatically hop to a new clear frequency. Wireless has never been easier! The system includes the GLXD4 receiver, the GLXD1 bodypack transmitter, the PGA31 cardioid condenser headset microphone with windscreen, and SB902 rechargeable Lithium-ion battery, which gives you up to 16 hours of continuous use per charge. Need wireless? Get smart - go digital, with the Shure GLXD14/PGA31 Digital Headset Wireless System.