The 18-36x 50mm prism design offers versatile magnification ranges for any application, while the multi-coated optics deliver awesome visual command during dawn and dusk. With waterproof, fogproof housing, every model is built for the long haul. Designed to be air tight, so moisture stays out even when submerged in water. Designed to be air tight, so moisture stays out even when submerged in water.Black with Straight eyepiece Waterproof Construction - O-ring sealed optics stay dry inside, even when totally immersed in water. Fully Multi Coated - Multiple layers of anti-reflective coating on all air-to-glass surfaces deliver bright, high-contrast images.