For Presenters and Performers, SM58 Cardioid Mic/Transmitter, Single-Channel Tabletop Receiver, 123 Auto-Scan Frequencies, Internal Antenna Diversity, 14-Hour AA Batteries, Expandable to 12 Mic Channels/300' Range. The Shure BLX24/SM58 brings performers and presenters a cost-effective wireless handheld microphone system with quality sound simple setup intuitive operation and dependable performance right out of the box. It includes the compact and lightweight BLX4 single-channel tabletop receiver with internal antennas ideal for portable use. The BLX24/SM58 also includes a handheld transmitter equipped with the legendary SM58 cardioid dynamic capsule an industry standard for vocalists and announcers. The receiver features one-touch QuickScan frequency selection to quickly search 123 available frequencies and locate a clean RF channel in case of interference. The system provides up to 14 hours of continuous use with two AA batteries at a range up to 300'. Up to 12 mic channels can operate simultaneously in each frequency band. This streamlined system is well suited for live performances and events in small venues wedding halls and houses of worship as well as conference educational and corporate facilities.