This North States pet gate is 31 inches high and is adjustable to fit into a range of doorway sizes, using pressure to hold the gate in place. It sat solidly in my entryway 47 inches wide, and it will expand to an even larger width. I used it for a rabbit, so some of the paint is gnawed off; otherwise, it is in good condition and clean.
While this posted item is not exactly the same, it's from the same company (North States) and will give a sense of how the gate works: