You are bidding on an original instruction brochure for a Western Electric Vacuum Thermocouples. It is dated I-A-25-5, WECO-T-761.  The condition is fairly nice, except the spline is loose below the first staple, and it does show its age.  It has 10 slick paper pages in 7 3/4 by 10 1/2  inch format, with hard paper cover.  It show the inside of various thermocouples, and gives characteristics.  I had not seen this data previously.  It should be great for your archive.  Shipping weight is 8 ounces, encased in cardboard.   Please see my other auctions for more interesting radio and audio items, and tubes.