Features: Adopting ultra highly frequency 730Hz acoustics transmission, antiinterference, and ultra short delay. Supports the simultaneous use of 4 set of devices, with a maximums transmission range of up to 50meters. Builted in rechargeable lithiums battery, long working time, equipped with USB cable, convenient charging. Plug and play, simple to use, small in size, light weight, and easy to carry. Suitable for guitar and bass, also for violins drum and other electronic music instruments. Specifications: Material: ABS plastic, coppers, electronic Size: As shown in the picture Frequency response range: 20Hz-20kHz Frequency: Highly frequency 730mhz Transmission range: maximums 50m (unimpeded); 30m (through wall) Transmission delay: less than 4ms Power supply: Builted in 3.7V600mah rechargeable lithiums battery Note: Please allow 1-2cm errors due to manual measurement, make sure that you 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: 1x Receiver 1x Transmitters 1x Charging Cable 1x Instruction Manual