Icom external VFO knob. Connecting to remote connector. Works for ICOM 7300/9700/7600/ 7610/7700/7800/7300mk2 or any other ICOM transceiver which support 19200bps trought remote connectoor.. Made in USA by WB4AAA LAB. Can be powered up from ACC connector. Cable supplied. Or from the USB port of computer or mobile phone charger with 5 volts if you need ACC for something else. Can change frequency, frequency step, rit, volume, switch Preamplifier, attenuator on and off. Device is fully tested on ICOM 7300 and 9700. Doesnt block USB port to use with external control software.For more questions contact PM. How it works shown on the attached video