I have used a very similar one of those. Can't say I particilarly liked it, I tried it with a bridle.
The one I got only came in one size and wasnt adjustable. And while it seemed to small for even a cob size horse, as it kinda pulled the bit upwards in the mouth and didnt look very comfy. The top also slipped down over the horses nose when he was being lunged, so it really didnt stay were it was meant to nor did it seem to fit how it was meant to, there just wasnt enough there to keep it in position or sitting comfortable. I didnt try it with a halter so maby it would be different...but I wouldnt think it would be much difference.
I would stick with getting a proper caveson in my experience.