This universal outdoor model uses high-index BaK-4 prisms and large 42mm diameter objective lenses to provide clear, bright vision. Their waterproof, fogproof and dirtproof design helps ensure great results. Their sleek body and sure-grip provide for comfortable handling. And their long-eye-relief (18mm) capability and twist-up/down eyecups let you enjoy using them for extended periods of time. Waterproof and fogproof design so you enjoy a clear view no matter what. Hermetically Sealed And Nitrogen Purged