Seiko 5 Sports GMT SSK001 Review: Is It Worth It?

The SSK001 reuses the SRPD case and adds a fixed 24-hour bezel insert split into day and night halves. The GMT hand is narrow with a lollipop tip so it stays legible without competing with the main handset. In grey and black the two-tone insert is subtle; the blue-and-red SSK003 is considerably louder.

The 4R34 adds a fourth hand geared to 24 hours to the familiar 4R base: 24 jewels, 21,600 vph, hacking, hand-winding, 41 hours. The GMT hand is set independently through the crown. The local hour hand cannot be advanced on its own, which is the distinction between a caller and a flyer GMT.

Identical construction to the SRPD: screw-down crown, 100 m rating, brushed and polished steel. The bezel here is fixed rather than rotating, which suits the complication and removes a common point of wear.

A black dial with LumiBrite-filled applied markers, a date at three, and a printed 24-hour track that has to coexist with the main minute track. It is busier than the standard Seiko 5. The two-tone black and grey bezel keeps the day and night halves readable at a glance, which is the whole point of the 24-hour scale.

The five-link jubilee-style bracelet is more comfortable and better looking than the three-link fitted to the SRPD, but the end links are still folded and the clasp is stamped with three adjustment positions.

Lug-to-lug is unchanged at 46 mm. The additional 0.2 mm of case height over the SRPD is negligible; the difference on the wrist comes from the jubilee bracelet, which distributes 155 g more evenly than a three-link.

Seiko publishes the same -35/+45 seconds per day for the 4R34 as for the rest of the family. The GMT hand is driven from the same gear train, so it stays synchronised with the main display.