This is Bestop's new improved "bowless" top. The Trektop NX features removable windows, factory style-door surrounds, Sunrider sunroof features, and factory-style header bar. The Trektop NX takes away the top bows and frames, and uses the Wrangler sports bars to give it shape and support. This gives the top a fastback or "raceback" look that's stylish, and different than factory or Supertops.