Model A Ingersoll 1/2 inch drive air wrench in good working condition- tested too.  some blemishes as photos show.  Includes boot as shown in photos- grease exists under boot- I pulled back boot enought to read model A and of Ingersoll- I do not see model number 231 and believe it may have worn off the tag- it looks like a 281 model in my thoughts- please verify with your own final determination- it's quite a wrench at the price!