SKX013 Sports 38

One 38mm case architecture. Two bezels. Five ways to build it.

SKX013 Sports 38 is the whole family - every case built on the platform we drew to be among the thinnest NH-compatible sports cases on the market. 38mm across the case, 40mm across the crown guards, 46mm lug-to-lug, 20mm lugs, 316L steel, crown at 3 o'clock. The dimensions of a daily driver, the lineage of a tool watch.

Getting there meant rebuilding the case body from scratch. Every internal dimension was re-engineered to compress height without compromising structure - which is why the bezels, ceramic inserts and sapphire crystals are dimensionally exclusive to this platform, and why we ship them pre-fitted and pre-aligned at our Singapore workshop. No fitting the rotating bezel yourself, no sticking and aligning the ceramic insert, no crystal-pressing the sapphire. That is the hardest, most finicky workshop time in a sports build - done for you.

What we kept open is what modders actually want flexibility on: SKX-style crowns, SKX013-spec chapter rings, 28.5mm Seiko Mod dials, hands, and the NH-series movements.

Two lines, one case

The family splits by what the bezel does. Everything below the bezel is shared.

SKX013 Diver 38 - three cases A unidirectional 120-click dive bezel with a 60-minute ceramic insert. From 10.86mm. Black, Green, and Origin - the one that wears the SKX013's own bezel pattern rather than the modern sub-style track.
SKX013 GMT 38 - two cases A bidirectional 120-click 24-hour bezel with no click spring at all - indexed instead by twin spring-loaded pill detents sunk into the case. From 11.26mm. Pepsi and Batman.

The five

Case	Bezel	Insert	From
Diver 38 Black	Unidirectional 120-click	Black ceramic, sub-style 60-minute track	10.86mm
Diver 38 Green	Unidirectional 120-click	Green ceramic, sub-style 60-minute track	10.86mm
Diver 38 Origin	Unidirectional 120-click	Black ceramic, SKX013-pattern minute-dot track	10.86mm
GMT 38 Pepsi	Bidirectional 120-click, pill-detent	Blue and red 24-hour ceramic	11.26mm
GMT 38 Batman	Bidirectional 120-click, pill-detent	Black and blue 24-hour ceramic	11.26mm

"From" is the total case thickness with the Ultra Thin solid caseback - each case's slimmest build. Thicker solid and sapphire casebacks add height in exchange for a 200m rating or a view of the movement.

What every case in the family shares

Dimensions. 38mm case diameter, 40mm across the crown guards, 46mm lug-to-lug, 20mm lug width. 316L stainless steel, brushed lug tops and mirror-polished lug sides, Swiss production quality, ISO 9001 certified. Screw-down crown at 3 o'clock.

Movements - and the two lines differ here. Every case takes Type M movements only; the Ultra Thin profile leaves very tight clearance between the hands and the sapphire, and Type L will not fit. The three Diver 38 cases take the NH35, NH36, NH38, NH70, NH71 and NH72. The two GMT 38 cases take the NH34 and nothing else - they were drawn around it, which is where their extra 0.40mm goes: the NH34 stands 7.99mm against 7.59mm for the three-hand NH calibres. Confirm your movement type before ordering; the family is recommended for experienced modders.

Parts you'll add. An SKX013-spec chapter ring (required - it seats the dial at the correct height, and the same chapter rings fit every case in the family), a crown from the five SKX-style options, a 28.5mm dial, hands, and a movement. On the GMT 38 the dial must be a GMT dial and the hand set a four-hand GMT set. Bracelets and straps are 20mm.

Bezels and inserts are not cross-compatible. Each bezel is dimensionally exclusive to its own line. A Diver 38 bezel will not fit a GMT 38 and vice versa, standard SKX bezels and inserts fit neither, and ours will not fit a stock SKX. They ship pre-fitted; replacement parts come from us.

One platform, thinner than the watch it takes its name from - and now it turns both ways.