The classic roof-prism design combines with 10x magnification for optimal viewing experience. PermaFocus Technology - Keeps distant objects permanently in focus, eliminating the need for constant adjustment. Nitrogen Purged Fog-Proofing - Nitrogen inside the scope ensures interior optical surfaces won't fog due to humidity or rapid temperature change. Multi-Coated Optics - Multiple layers of coatings on all lens surfaces increase light transmission and image brightness.