The Flight E-Type Straight Nose Cone is both Kavo (F-424BZ) and NSK Compatible (F-415BZ). It’s attachment goes on any e-type air motor or electric motor. The F-415BZ is a no water straight nose cone used for tooth removal and right angled prophy heads for polishing. The F-424BZ is a KAVO compatible straight nose cone which can go on air motors and electric motors with a speed up to 40,000 rpm. These affordable yet durable straight nose cone slow speed handpieces are suitable for lab use, hygiene use and dental use. 1 year warranty.