Featuring the BETA 87A vocal microphone, the Shure GLXD2+/B87 dual-band vocal mic with handheld transmitter delivers superior, transparent digital audio. GLX-D+ wireless systems combine Automatic Frequency Management technology with best-in-class intelligent lithium-ion battery rechargeability and dual-band (2.4GHz and 5.8GHz) wireless frequency capability. This system includes a GLXD2+ handheld transmitter, an SB904 lithium-ion rechargeable battery and a swivel adapter.