U-Series\nThese compact, inverted porro-prism models feature a durable dual-axis, single body design with synchronized IPD adjustment and full multi-coating for better light transmission. Aspherical lens elements give you edge-to-edge sharpness. They are a perfect “utility” companion for a multitude of applications.\n\nThis line-up takes a different approach. The dual-axis and inverted porro prism design makes it compact and light weight. Combined with aspherical lens elements for edge-to-edge sharpness, BaK4 prisms and multi-coated lenses you get a star performer ideal as a travel companion, for outdoor events or for general purpose usage.\n\nNew Fully-multi-coated optics\nFully multi-coated lenses serve the essential purpose of maximizing the amount of light passing through a lens, thereby prevent flare and ghosting from interfering with your view. PENTAX applies multiple layers of coatings to every surface of every element and prism in the full Sport Optics line-up. These fully-multi-coated optics assure the maximum light transmission resulting in a clear, crisp view of the world.\n\nBaK4 prisms\nDue to its outstanding refractive index, the BaK4 glass prism found in all PENTAX Sport Optics is highly acclaimed for its perfectly round exit pupil and clear, unvignetted image.\n\nAspherical lens elements\nEdge-to-edge sharpness is a vital element to comfortable viewing. To achieve this, we utilise aspherical lens elements in our eyepieces. This is a specially shaped lens design that reduces aberration to a minimum.