Featuring the industry-standard BETA 58A vocal microphone, the Shure GLXD2+/B58 dual-band handheld transmitter delivers superior, transparent digital audio. GLXD+ wireless systems combine the leading edge of 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 the GLX-D2+ handheld transmitter, an SB904 lithium-ion rechargeable battery and swivel adapter.