Feature: Smallest size, lightest earphone monitor. 2.4G wireless technology, low delay, no compression; Support to connect with phone for recoding Support stereo and mono Description: Wireless frequency band: 2.4GHz Delay: ≤12ms Effective distance: ≤30 meters outdoor distance or 15 meters wall distance Battery capacity: transmitter 780mAh, receiver 550mAh Dynamic range: Greater than105dB if your band have more people, you need the extra receiver, you can pick this one. Material: ABS colour: Black Package Contents: 1 x Transmitter 1 x Receiver 1 x USB cable 2 x Audio cable 1 x English instructions Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.