Bushnell Natureview 8 x 40 Birder Combo Birding combo includes binoculars, birding CD-Rom, birding field log, carrying case, and deluxe strap 8x magnification by 40-millimeter objective porro binoculars BK-7 porro prisms with multi-coated optics for clear bright images Textured center-focus wheel for easy adjustments and rugged, non-slip rubber armor Fold-down eyecups for eyeglass wearers; limited lifetime warranty