The U4 IN-EAR MONITOR is a high-quality wireless system with a 5-hour battery life and a reception range of 90-100 meters. I purchased it a month ago and have used it about 3 times. It works without any problems. All accessories, including the manual and cables, are included. - Model Name: U4 IN-EAR MONITOR - Wireless System: 2.4GHz Wireless System - Frequency Range: 20Hz-20kHz - Output Types: Mixer, Line Output, Headphones, Earphones - Battery Life: 5 hours of use - Reception Range: 90-100 meters - Supported Sampling Rate: 24-bit/48kHz - Accessories: Transmitter, Receiver Thank you for looking.