C4AD Calculite Evolution 4.5 Inch Open Downlight Trim features 50 degree physical and reflected cutoff. Die-cast aluminum neck insert dissipates heat. Full cone reflector eliminates light leaks. Unitized optics ensure consistent performance. 1.25 inch maximum ceiling thickness. Ceiling Cutout 5 1/16 inch. Available in White trim with Clear, Comfort Clear Diffuse, Specular Gold, or White reflector, or Polished trim with Clear, Comfort Clear Diffuse, or Specular Gold reflector. One 120 volt, A-type medium base incandescent/halogen/LED lamp is required, but not included. A complete fixture includes a frame-in kit and a trim kit, sold separately.