This is a custom-made pre-amp encased in a metal project box for improved reception of UHF military satellite transponders.   I had two of them custom-made for me by a retired TRW engineer to improve my reception of voice & data signals sent by the US military satellites -- it's centered on 260MHz but should improve both SATCOM (US or non-US) and AM Air/Ground signals in that general frequency spectrum.   

    Alas, I cannot recall if it uses MOSFET or GaAsFET to boost the received signals, but it does offer a great signal to noise ratio, with about 8VDC power (via a 44" power cable with an RCA connector).        This one was my spare one, so it only has about 5 hours use time on it.    Selling it as [part of reducing/consolidating my radio room gear.

  One BNC connector (marked I, as-in INPUT) attaches to your antenna, the second BNC connector is the output, which you'd connect to your receiver.

 Shipping would be via USPS Priority Mail, Flat-Rate Small Box.