The ridden grey in my siggie has a neue schule verbindend which is loose ring and the chestnut in hand has a NS pelham in, dont know if you can see them very well, if not, i'll try and post a piccy! xx
Just because I have one for my lad which I bought yesterday. he takes a 5.5 inch normally, so ordered a 5 and 3/4 as they seem to come up small, but I still think it's too small for him...
My horse usually has a 5.5 and the NS was too small when it arrived so sent for the 5.75 and thought there wasn't much difference but its actually ok and when riding its not rubbed as the contact takes the edges up.
Some photos of it without the contact taken up. Its the NS verbindend 5.75 on a 16.2hh horse.
I was unsure about the 5.75 as my horse has fat fleshy lips, hence getting the 12mm too, but its been fine and I think the 6" would pull out the side of his mouth quite a fair bit when in use so glad I stuck with the 5.75. My instructor thinks its perfectly fine. My horse likes it and he has been working lovely in it too!!