Barska 10x40 Blackhawk Monocular BK7 Green Lens Black. The Barska 10x40 Fogproof Blackhawk Monocular w/ Green Lens has an O-ring sealed for complete waterproof protection dry nitrogen purged sealed to prevent fogging clouding and moisture damage. The Barska 10x40 Blackhawk Monocular w/ BK-7 Prism has multi coated optics for increased clarity BAK-4 or BK-7 prisms for crisp images and large knurled center focus knob for precise focusing. The Barska 10x40 Waterproof Blackhawk Monocular comes complete with a non-slip diamond textured rubber design for a secure grip and shock-absorbing rubber armor. Specifications for Barska 10x40 Blackhawk Monocular w/ BK-7 Prism: Magnification: 10x Objective Lens: 40mm Waterproof: Fogproof: Prism type: Roof Prism Glass: BK-7 Exit Pupil: 4mm Multi Coated: Main Focus Wheel on Body: Field of View(ftat1000yds/mat1000m): 344/105 Close Focus (ft/m): 13/4 Eye Relief: 17.5mm Weight: 4.8 oz Features of Barska 10x40 Blackhawk Monocular BK-7 Roof Prisms Multicoated Optics 60 Wide-Angle FoV Diamond Pattern Rubber Grips Nitrogen-Filled Waterproof and Fogproof Knurled Eyepiece Focus Wheel Fold-Down Rubber Eyecup Rubber Armored Body Focus System Center Magnification (Fixed) 10x Close Focus (ft/m) 13/4 Eye Relief 17.5mm Objective Lens 40mm Exit Pupil 4mm Field of View (ftat1000yds/mat1000m) 315/105 Package Contents: Barska 10x40 Fogproof Blackhawk Monocular w/ Green Lens Carrying case Neck strap Limited Lifetime Warranty Barska AA12132: 10x40 Blackhawk Monocular BK7 Green Lens Black