Mine reaches from the stall ceiling to the ground, and touches the ground when it starts to thin out. Sometimes Ahab can get the hay out, but other times it just sits there. I don't know if the hay is too coarse or if his ... well, I don't know why he can't work it sometimes, but he can't. I got the biggest size openings they offer.
I also built a steel frame and secured a net inside, like a sheet, which rides up and down inside a huge, sturdy plastic tub. But I am afraid he will get a tooth caught in the net, and, of course, without a grid bottom old hay quickly piles up. Even after a day or two the bottom layer it is inedible.
I actually meant the way they work and grind and grow is affected if the horses heads are raised rather than teeth getting stuck. Out equine dentist was very against the use of hay nets.