QLXD2/SM58Handheld Transmitter with SM58 Capsule Details: 24-Bit digital audio quality Incredibly efficient RF spectrum usage Quick syncing with a wireless receiver over IR at the push of a button Clear, uninterrupted signal over the entire operating range AES 256-bit encryption for secure transmission Over 120 dB of dynamic range: no transmitter gain adjustment needed 1, 10 mW selectable RF output power Optional Shure SB900B lithium ion rechargeable battery reports remaining runtime in hours and minutes External charging contacts for docked charging Backlit LCD with easy to navigate menu and controls Selectable display mode showing group/channel, frequency, or battery runtime Rugged metal construction Frequency and power lockout The QLXD2/SM58 Handheld Wireless Microphone Transmitter works with QLX-D Digital Wireless Systems.