Rechargeable Built-in UHF Wireless Guitar System Transmitter Receiver,Wireless transmitter & receiver set for electroacoustic musical instruments like guitar, bass, etc. Uhf 730mhz sound transmission, anti-interface and ultra-short delay, giving you the best . Supports 4 sets of devices that work at the same time, one-to-one; and maximum transmission range is up to 50 meters. Built-in rechargeable lithium battery, long hours of work; and comes with usb cable for convenient charging. Plug and play, simple to use; compact and size, easy to carry. Audio response range: 20Hz-20KHz Frequency: 730mhz ultrahigh frequency Transmission range: max.50m (without obstacle); 30m (through the wall) Transmission delay: less than 4ms Power supply: built-in 3.7v 600mah rechargeable lithium battery Charging port: micro-usb Colour:Black Material:plastic Size:11 x 4.5 x 1.5cm Package Contents: 4 * Transmitter 4 * Receiver 4 * USB Charging Cable(random color,The specified color is not accepted) 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.