The pair incorporates natural hues in the bezel and dial, and instead of a
link bracelet or rubber strap, they come on Seichu fabric straps. According to Seiko, Seichu is a traditional Japanese braiding
link technique that results in a strap that's four times stronger than other Seiko fabric straps. The watches ship with two; the SPB239 comes with black and desert khaki Seichu straps, while the SPB237 comes with olive
link drab green and admiralty grey Seichu straps.