Military Mark 7 Knee-mounted Chart-plotting Board

Mark 7 knee-mounted chart-plotting board.Used in very good shape comes with original instruction.The Mark 7 Chart-plotting Board is a combination chartboard,computer and small area Mark 3 type plotting board.It mounts on the pilot's leg so that it may be used in any type of Naval aircraft.It is provided with a self-contained lighting system which enables its use during night or high-altitude flights.In addition,several other features have been provided in an effort to incorporate desirable suggestions recieved from fleet Pilots.You can calculate speed,time,distance,fuel comsuption and other similar computations may be made with the aid of the slide rule scales located adjacent to the compaas rose.I don't know if the lights work ,cuase i don't have a way of getting the tye of batteries it takes.Cashiers check,m.o.,paypal next day ship.$7.50 s/h. inlower 48 U.S.A.All other bidders please contact me for s/h, price.Please send funds within 7 days end of auction.Thanks