The original narrow twist dressage model I believe was called the Style. I had one made in the late 80s/90 ish and loved it. Then came the SL and then the SLK, then the SLK platinum. They all were variations of the same tree I believe and definitely the same twist. I’ve had one of each and they’ve all worked for me, not so much for all of my beer keg shaped beasts but it’s still my go to if I can modify it to fit my beast of the day. At the moment, however, I have an Albion K2 which is working for my homebred. His father went very well in the SLK I had for him.