The Fujinon Polaris 7 x 50 FMTR SX binoculars are among the best and most widely used binoculars in the field of marine and astronomy applications. They feature a flat field distortion free eyepiece that is compatible with many optional filters. This feature makes it ideal for astronomical applications. The binoculars feature 23 mm of eye relief, which makes them convenient for use even when wearing sunglasses in bright conditions. The Nitrogen-purged waterproof and fog proof body makes them highly efficient and rugged even in very humid environments. They give you a magnification of 7x with an object lens diameter of 50 mm.