These Waterproof, Fogproof and Nitrogen filled binoculars are a rugged and reliable pair of binoculars ideal for birdwatching, and all nature based activities. With a 3 year warranty and rivalling the performance, quality and finish of Nikon, Pentax, Vortex, Zeiss, Bushnell and many other mid to high level binoculars at a very affordable price. They have fully multi coated lens and silvered, phase corrected BK4 prisms. They incorporate Bosma's trademark SBC (Super Bright Coatings) for high light transmission. The body of the binoculars feature a rugged rubber armour, twist up eyecups and Diopter adjustment. In the field, they have among the closest focus of all the Bosma Binoculars at just 2.5m away, great for seeing those small hard to identify birds in a closed forest environment. On the technical side of the optics, they have an exit pupil of 4.2mm and generous eye relief 15mm. The field of view is 104m at 1000m range. The IPX7 waterproof rating ensures they are truly waterproof standing up to the harshest conditions.