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Nikon ProStaff 4-12 x 40 Black Matte Riflescope (BDC)
Compact riflescope with 4 to 12x magnification and 40mm objective lens
Fully multicoated optical system transmits up to 98 percent of available light
Zero-reset turret with spring-loaded adjustment knob 37 inches of eye relief
Nitrogen-filled O-ring-sealed housing for waterproof fogproof performance
BDC reticle quick-focus eyepiece measures 141 inches :