About 5 1/2" x 8 1/2". Someone folded it over to stuff in a back pocket but it is not badly creased and otherwise not terribly worn or aged; however the one staple holding it together is rusted. (Not too difficult to take it out and wiggle a new on in there, don't attempt to use a machine just fit it in by hand. I will do it for you if you like, haven't done it yet because some people like these things totally original rusty staples included.) Comes with an insert sheet which consists of several problems involving wind speeds; I expect that few copies survive with the sheet present. But either way we are not asking much for this and it makes a good addition to a collection of early air power memorabilia. Manual TM 1-900, marked as Advance Copy and with a couple of official looking bits stamped on it. (The math involved is no better than ninth or tenth grade so no great secrets here but still an interesting document.)