Bushnell 10 x 42 Natureview Plus Binocular 10x magnification, 42-millimeter objective binoculars with lightweight and rugged roof prism system BaK-4 prisms and fully multi-coated optics for improved light transmission, image clarity, and brightness Rugged, shock-absorbing, non-slip rubber armor; textured center focus knob 100 percent waterproof/fogproof: O-ring sealed and nitrogen purged Designed for birding and wildlife viewing; limited lifetime warranty