Alpen Apex XP 10x42 ED BinocularsApex XP binoculars deliver vibrant images rich in detail even in low light conditions through a combination of high resolution ED (extra low dispersion) glass that enhances luminosity and contrast, superior BaK4 prisms, unique PXA phase coating and HR metallic coatings. Each rugged Apex XP binocular is waterproof for all weather performance and purged with nitrogen gas to create an internal environment that is impervious to fogging.