FIF- no info, and def not a long term fix, but if you have been working for awhile, getting your squat up etc, will DEF gain some inches in a month- basically a good change up or peaking block. Not going to take you to a 40 inch vert from a 30.
The name is kind of sketchy, but I do believe the people kelly tested it on gained an average of 3.8 or something inches, but obviously some wont gain that much