Citizen has unveiled many stunning models at Baselworld 2016. And the Eco-Drive One cought many people’s eyes. It is the thinnest solar-powered timepiece. The Eco-Drive One will be available in three general release models—the AR5000-50E, AR5000-68A, and AR5004-59H (stainless steel case with cermet bezel)—as well as the limited edition AR5014-04E. Cermet is a high-end composite made of ceramic and metallic materials, and is prized for its relative hardness and versatility in terms of finishing. Citizen is not the first watch company to use cermet; Jaeger-LeCoultre and Audemars Piguet have in the past played with different metal/ceramic alloys in their cases and bezels. The use here, however, seems to be functional as a much as it aesthetic, since a 3mm case would arguably require some reinforcement to avoid bending.The Citizen Eco-Drive One Limited Edition case features a rose gold-toned cermet case and polished tungsten carbide bezel mimicking the appearance of stainless steel. The general release models feature stainless steel cases with Duratect, Citizen’s proprietary surface hardening technology, and cermet bezels. All four models boast a three-part construction, with the bezel and case back flanking the mid-case with four screws visible from the top. The case sizes are delightfully tempered, coming in at 38.15mm for the LE, and 39.8mm for the general release models.