This bullhorn bar stays within a single plane and can be thought of as a straight handlebar with a couple of bar ends attached, except lighter and neater. So the horns point in slightly and you mount it pointing about 30 degrees upwards. The internal diameter at the ends is narrow at 16mm due to the thick wall diameter so problematic for bar end levers, but with diameter a typical flat bar 22.2mm you might want your brake lever(s) on the middle section.