Seiko 5 Automatic 21 Jewels SNKE54 SNKE54K1 SNKE54K Men's Watch The Seiko 5 is an extremely reliable watch with a fully in-house built movement; in fact, the whole watch has been created in Seikos own facility. Despite its gorgeous looks, it needs very low maintenance to preserve its inner and outer goodness. Donât let the movement stop running ever; always polish it clean after taking it off every time, once a week under running water.