Alpen"s 10x42ED Wings binocular is an open hinge design for lightweight and comfortable viewing with superb optical quality. The ED "extra low dispersion" glass is achieved through the use of fluorite glass which provides the very best in color fidelity and contrast in all light conditions. With Alpens fully multi-coated and PXA phase correction coating, the Wings ED binocular delivers outstanding performance that provides superior viewing to satisfy even the most serious binocular user. All Alpen Wings binoculars are fully waterproof, fogproof, provide long eye relief for eyeglass wearers and twist up eyecups for comfortable viewing with or without glasses. Backed by Alpens lifetime warranty.