I've been told that I can use this tool to diagnose ABS problems on my 91 Deville but wanted to see if anyone has any experience with it before I purchase it. I'm purchasing from e-bay so it may not come with a manual, so I'm trying to get all the info on it that I can before I purchase. Any info will be Greatly appreciated. Thanks.

Break out box is relatively simple to use but it will rely on overlays and adapters to be able to use it. You will also need FSM with out it won't be of much help.