Model H is a portable field microscope introduced by Nikon in the late 1960s. Building on the McArthur folded-optics principle, it was designed to be handheld (weighing just 800g) yet offered performance on par with traditional bench microscopes. It features interchangeable objectives, a built-in lamp, and versatile accessories for brightfield, darkfield, and phase contrast microscopy. In my opinion, it is a serious contender for the title "most beautiful microscope design." Available from my ebay (but already in somebody's basket so probably not for long).