Designed to work with Zeiss and Zeiss type (Topcon, Moeller, etc) microscopes. Easy to operate with steam sterilizable knob. Short profile for use with all fixed and inclinable eyepieces. No light loss in upright mode. Virtually no image shift when switching between upright and inverting modes. Crystal clear optics. Compatible with all wide angle inverting vitrectomy lenses. Available with Ocular Wide Angle Vitrectomy Lenses.