GPO Passion 10x42HD BinocularGPO Passion 10x42HD Binoculars provide 91% light transmission thanks to Double HD objective lenses (extra low dispersion lenses that are chemically laminated to create a single multi layer high performance lens), GPObright lens coatings which pass 99. 7% of the light that passes through each air to glass surface. This process reduces surface light reflections, enhances resolution and color contrast, minimizing chromatic aberration. External lenses