Features: The built-in lithium-battery provides a 10-hour (normal) battery life for longer, and uses stable wireless technology; The wireless audio transmitter and receiver system with screen dispaly; Stable wireless connection within 30M/98.4feet (normal), Stable wireless signal transmission, low delay. Frequency Response Rate:20Hz-20KHz Sampling Ratio:24bit/48kbps Audio Specifications: Material:Plastic+Metal Frequency Response Rate:20Hz-20KHz Sampling Ratio:24bit/48kbps Audio Working Distance:30m/98.4ft Option Type:1Set Wireless Microphone System without Microphone;1Set Wireless Microphone System with Microphone; Note: Please allow 1-2cm errors due to manual measurement,please make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1xTransmitter 1xReceiver 1xUSB Cable 1xAdapter 1xManual