Re: Shimano 600 Ultegra aero seatpost, 27.2mm
That's for the microadjust - the saddle is tightened almost all the way with the main bolt, then turning the allen bolt on the front adjusts the angle until you get it just right, then the main bolt is tightened all the way. There's infinite adjustability within the range of it, it doesn't have a series of notches as other one bolt seatposts do. I'll sort you some more pics tomorrow!