Tuneable UHF Handheld Microphone SystemTuneable UHF Handheld Microphone System Single channel PLL tuneable UHF wireless system with a handheld transmitter. The receiver unit is compatible with standard 19" racks using the included rack ears and front mounting antenna accessories. The RF carrier frequency is selected on the receiver and synchronized to the transmitter via infra red at the touch of a button. Up to 4 RU105 systems can be operated together on the EU licence free band. PLL