Waterproof and nitrogen purged to prevent fogging the echelon 20x70 binoculars by celestron are perfect for low light observation and astronomy constructed from lightweight aluminium alloy the binoculars have a durable rubber armour covering for a slip free grip and added protection and boast superior bak 4 prisms for maximum contrast and sharpness they are hand assembled in the usa and utilise celestrons proprietary xlt coating technology for amazing optical performance as well as this