Prospex Street series was developed to combine looks and substance: coupling Seiko fans enthusiasm for watch design styles alongside the expertise from 5 decades of creating diving watches. The retro tuna shape from the 1975 divers model has been channeled into a more compact yet reinforced watch, robust enough to dive 200m under the sea but stylish enough to be worn on the street.The watch shape is affectionately nicknamed by Seiko fans as a Tuna - because of its larger diameter and bold shape like a tuna tin.The accordion-style silicone strap combines high durability and comfort - a strap design invented by Seiko in 1975 as a practical solution to the expansion and contraction of a diver's wrist at different depths.