They're not "boots" in that they don't cover the whole foot, just the back of the shoe/heel bulb.
I got a pair a couple of months ago for my gelding who pulls shoes all the time. As a side note, I have a great farrier and we've tried just about everything to keep the shoes on to no avail.
The shoe secure things have been a godsend! It's a little annoying to have to take them off to ride and put them back on, but way less annoying than walking the field to find a shoe.....again.
My only complaint is that I wish they were a little thinner on the bottom. They effectively wedge the foot a bit, and so I'm leery about leaving them on 24/7 when the ground is firm (I don't worry about it as much when it's muddy out).
The company also has a "ride in" model, and I'm really interested to see how those differ.
__________________________________ Forever exiled in the NW.