Effective objective lens diameter: 115 mm; Exceptional Design: This spotting scope system combines exceptionally flexible modularity with optical perfection; The objective lens can be changed to suit any viewing situation; SWAROVISION Technology: Extreme detail recognition is offered at crucial moments thanks to SWAROVISION technology; Fluoride-Containing HD Lenses: Field Flattener lenses provide unprecedented peripheral definition, fluoride-containing HD lenses minimize color fringing, while optimized coatings ensure maximum color fidelity; The 115mm objective module raises the bar with the largest lenses on the market; This gives you a crucial benefit, particularly at dawn and dusk