This device lets you switch two mics between two tranceivers at the touch of two buttons . You configure it using internal jumpers. MFJ has the jumper combinations for some radios but it's far from a comprehensive list, so some trial and error may be required. I don't have the manual but you can download it from MFJ. I am selling it because I have an ICOM transceiver with an electret mic requirement in the mix now with a non-ICOM transceiver and a dynamic mic. So swapping is not an easy option. I used it for a number of years to swap a Heil dynammic mic and a Kenwood hand mic between my Flexradio 6300 and Kenwood TS2000.
I'm asking $75 cash. It sells new at HRO for $129.00 and $139.00 at DX Engineering.
I can meet at the club most evenings.