The Sony DWTP01/4250 Digital Plug-on Transmitter. The DWT-P01digital plug-on transmitter /4250 model operates within a 60 MHz range, from 638 to 698 MHz. Audio input is selectable from either mic or line level. The DWT-P01 provides a choice of 1, 10 or 50 mW RF output. The transmitter operates for approximately 3.5 hours using two AA size alkaline batteries at 10 mW output power. The DWT-P01 supports use of alkaline, lithium, or nickel-metal hydride batteries. Transmitter functions; including input attenuator, RF frequency selection, RF power output, Audio LCF frequency and a power sleep mode (in the transmitter) can be remotely controlled from the digital wireless receiver. The DWT-P01 also includes 48V phantom powering.