Celestron 71340 Outland X 8x25 Compact Roof Prism Binoculars, BlackMULTI COATED OPTICS AND BaK 4 PRISMS: Multi coated optics help obtain high resolution and high contrast views, prisms made of BaK 4 glass give enhanced colour fidelity; Enjoy crisp, detailed views and dependable performance WATERPROOF AND FOGPROOF: Designed to withstand all weather conditions, our Outland X compact binoculars have been filled and sealed with dry nitrogen gas for rigorous outdoor use without internal fogging of the lenses PROTECTIVE