Any brand IEM set to transmit 50 mW or less may be used, as well as any type of directional antenna. It also provides DC power to up to 8 IEM transmitters with an external power supply, removing the need for wall warts. IEM transmitter combination is important for multi-channel systems to minimize intermodulation artifacts arising from multiple adjacent transmitters interfering with one another. The CP Beam antenna is a recommended accessory for the COMBINE8 and is available with in a bundled package. The COMBINE8 is also sold bundled with CP Beam Antenna (CPB). This turnkey bundle includes everything needed to configure up to 8 channels of In-Ear Monitors. Including Premium made in USA low loss double shielded coaxial cabling coax cable.