He was already used to a regular snaffle. I had to start him from basics when I bought him so he was lunged with my old sweet iron snaffle for a couple of months and ridden with a bitless training sidepull. I then used a "fulmer" on him and my trainer at the time wanted me to switch him to a Sprenger (the one that looks like the one I linked too). We just put it on him and he pretty much went right away in it and seemed much more happy. It took about 5 rides or so for him to get really used to it, but he had a bad reaction to the Aurigan (the metal in them) so I moved him to the copper one that I linked to and sold the other on Ebay. He has been happy with it ever since.
I did have one trainer try to get me to switch to a bit like it with a copper roller, but Cinny didn't really like the roller and it's not legal in the show ring anyway. I tried to use his old Fulmer once because his every day bridle was still drying from being cleaned, and he refused to move until I put his Copper Korsteel on it. Picky Picky. He will still work in the side pull though.