Built for functionality the nikon aculon a211 12 x 50mm binoculars has a bak 4 porro prism system that delivers a high quality image under a multitude of lighting conditions making these binoculars effective from dusk till dawn rubber eye cups facilitate easy positioning of eyes at the correct point and provide comfortable viewing centre focussing to allow you to quickly and easily adjust to different focal ranges porro prism lens diameter of 50mm magnification 12x rubber body twi