Note:the listing have two choice, the rechargeable box is not included if you do pick the cheap one. 2.4GHz wireless transmission, 24bit/48KHz sample rate. Delay: 105dB. Frequency response:20~20KHz,+1dB/-3dB. We support 3.5mm and 6.35mm plug,190rotating device, it is available for most of the electric instruments. You can use 4 groups of equipments at the same time. Battery capacity: Transmitter 600mAh,Receiver 300mAh. The way of power supply: you can use the USB cable to charge the Transmitter and Receiver . It can be used for 6 hours after Transmitter and Receiver fully charged.When the Transmitter and Receiver running low, you can use the USB table to charge them fully FAQ 1. Q: The device can not turn on. A: If the device is not used for a long time or when the battery is low, the power is not charged in time, will cause the battery to enter the protection mode, and it is necessary to charge the battery to activate the battery. 2. Q: The device can be turned on, but there is no sound at all. A: Check if the WIRELESS SYSTEM is in pairing now, if the pairing indicator flashing, you need to re-pair the Transmitter and Receiver. 3. Q: Strange noise when using. A: a. There may be strong electrical interference,or the transmission distance is too far, or the transmission obstacle is too much. Please minimize the transmission distance,or stay away from electrical interference. b. When the battery of instrument or WIRELESS SYSTEM run low,it will cause the noise.Please check your device. c.Check if the speaker has a secure connection ground, such as no land, is likely to be a current noise. 4. Q: The device is not charging properly. A: a.The battery will enter the protection status when it is in a low power state, so it is necessary to charge at least for 10 minutes.Can start the battery. b. Check if the charging cable is working properly. c.Check if the charging jack of this device is damaged. 5. Q: Can I use a Transmitter, multiple Receivers? A: Yes, let all the Receivers enters the pairing state,then let the Transmitter enter the pairing state.Complete the pairing. 6.Q:Can I use multiple Transmitters, one Receiver? A: Not support. 7. Q: When using, the power consumption of the Transmitter is especially fast, is it normal? A: It is normal, the Transmitter is use to transmit signal to the Receiver, so that the amount of work is high.The Receiver is only accepts the signal, so the amount of power consumed is not equal.