The original name was Adjustable Seat Bones, but friends thought that it sounded too hard. The surfaces are designed to provide individually adjustable portions that are contoured to support the bones on the bottom of the pelvic girdle and the closely associated muscle mass. This depends on what sort of riding you are doing. The horn can be used for steering or balancing. For riders on exercise equipment, the horn is not needed to steer, and balance is less of an issue.
Examples are casual mountain and cross bike riders who normally ride in a fairly upright position.
Road bikers or racers, on the other hand, usually set their handlebar height at or below their saddle height for aerodynamic purposes. These riders may need more fine tuning of both the bicycle saddle and handlebars to become really comfortable. But it is worthwhile if you want to eliminate long term damage to sensitive soft tissue. We are working on reducing the weight. The suggested positions for the front of the surfaces for women are just starting points.