receiver that operates as a wired and wireless bodypack to offer users a cost-effective upgrade, and greater flexibility A built-in limiter to aid in hearing protection that can't be defeated LED indicators for power, RF (radio frequency) signal strength, frequency, limiter and battery level Volume control An integrated cable management system to keep cables under control A 1/4" line input jack for convenient, integrated line input to connect monitor mixes, click tracks or effects Up to 6 hours, volume dependent, on a standard 9V battery  (less)