Alpen Apex XP BAK4 Fully Multi-Coated Optics, Waterproof / Fogproof  Roof Prism Binoculars - Includes Alpen&rsquo;s No-Fault, No-Problem Waterproof / Fogproof - Nitrogen filled Long eye relief to see full field of view when wearing glasses Fully Multi-coated - HR coated - Phase coated BaK4 high index glass Alpens no fault no problem lifetime warranty