"Flat" or "riser" bars are the standard handlebars equipped on mountain bikes, hybrids, and recently on fixed-gear bicycles and flat bar road bikes. A flat bar is a nearly-straight tube, slightly bent toward the rider. A riser is a variation in which the outer sections of the bars rise from the center clamp area. Flat and riser bars may be appended with bar ends, providing more hand positions. The bullmoose style is a variation on the flat bar, common on early mountain bikes, where the stem and bars are a single unit and where the single top section of the stem would be, there are instead 2 bars joined at the quill to the rear and connected to the conventional handlebar section in the front, at two off-center locations, forming a triangle.