Stereo/Mono switch: Stereo mode (the device outputs the signal fed into the left input to the left headphone and the right signal to the right headphone). Mono mode Channel L and channel R are mixed and output to both headphones. XLR INPUTS (L) and (R): Dual XLR balanced jacks connect to the input signal source. UHF frequency band (670-680MHz) and PLL frequency synthesized technology for stable. Working performance 6 selectable channels Powered by 2pcs AA batteries, low power consumption design for long playtime up to 12 hours Multiple sets of receivers can be operated with a single transmitter within the operating range Dynamic expansion circuitry for high S/N ratio Complex anti-interference circuit for using 6 sets at the same time without mutual interference Receiver LCD displays frequency, channel and battery level Long operating range up to 100m Currier frequencies 670.3/671.6/673.2/675.1/677.3/679.3 MHz.Recording studio monitoring, on stage monitoring. 4 x Receiver 1 x transmitter 4 x earphones Manual 1pc 9V/300mA power adaptor 1pc (110V-240V). The item "S2 In Ear Professional Stage Wireless Monitor System Receiver 4 Transmitter" is in sale since Tuesday, March 25, 2014. This item is in the category "Musical Instruments & Gear\Pro Audio Equipment\Speakers & Monitors". The seller is "photowoow" and is located in hongkong. This item can be shipped worldwide.