Bresser C-Series 8x42 Binocular Prism BaK-4 Roof. Bressers waterproof C-Series binoculars come in a versatile selection of sizes from compact 25mm models perfectly sized to slide into a backpack or pocket to the larger 50mm models that drink in light and are great for astronomy. In addition to a sleek roof prism design that is unobtrusive and easy to grip all models are made with premium BaK-4 prisms that are fully multi-coated for brilliant images rich in contrast. The binoculars have a waterproof casing and the optical barrels are purged with an inert gas to prevent internal fogging. Additional features include twist-up eyecups for comfortable viewing diopter adjustment that guarantees each eye is properly focused and a tripod thread for situations when extra stability is needed. Specifications for Bresser C-Series 8x42mm Roof Prism Binocular: Manufacturer: Bresser Color: Black Magnification: 8 x Objective Lens Diameter: 42 mm Prism System: Roof Prism Material: BAK4 Optical Coating: Fully Multi-Coated Close Focus: 10 ft Water Resistance Level: Yes Weight: 1.8 lb Magnification Type: Fixed Package Contents: Bresser C-Series 8x42 Binocular Bresser 90-00842: C-Series 8x42 Binocular Prism BaK-4 Roof