Barska's 10x50 X-Trail Reverse Porro Binoculars are built with high-magnification and large objects that work together to create an optic that is ideal for making detailed observations of subjects at long distances with enhanced low-light performance versus smaller-objective binoculars. Complimenting the larger objectives are ruby-red tinted anti-reflection lens coatings which further increase the low-light performance especially at dawn and dusk, or in woods with a heavy canopy. Specifically, the red tint increases the overall contrast and boosts the appearance of objects against blue and green backgrounds further helping you to pick out birds and game in the forested areas or in the sky. The combination of magnification and lens size translates to a wide exit pupil that ensures that when your pupil is dilated in low-light you will see the full view without vignetting. Its reverse Porro prism configuration positions the objectives to be closer to each other than those found in the classic Porro design, allowing for a more compact and smaller housing that fits comfortably in the hand.