Waterproof Binocular w/ Compass ( 7x50 Black)When you know that a binocular is fitted with BAK 4 Porro prisms, you know that the product is quality. A further testament to the quality is the fact that it has multiple lens and prism coatings. This magnificent instrument has a light transmission efficiency of just over 90% about as good as you get even in the top of the range units. So, we introduce the 7x50 Waterproof Binoculars with Compass and Rangefinder. This product weighs in at a hefty 1kg