Pentax's highly portable and functional 10x25 UP Compact Binocular employs an innovative unibody design that locks the objective lenses into the body with the eyepieces set on a synchronized dual-axis mechanism that ensures they stay symmetrical in relation to the center axis of the optic when adjusting the interpupillary distance. The 25mm objective lenses are fully multicoated to reduce reflection and maximize light transmission to produce the brightest images possible. Aspherical lens elements virtually eliminate distortion, especially around the edges, and corrects for lens astigmatism which can prevent sharp focusing. 10x magnification. BAK4 porro-prism optical design. Aspherical lens elements reduce distortion at the edges and corrects for lens astigmatism which can prevent sharp focusing. Anti-reflection fully multicoated optics. 262.5' field of view at 1000 yards.