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Spinnaker watch · automatic

Spinnaker Bradner GMT Automatic Orange Blue

The Spinnaker SP-5121-AA measures 42 mm across, 50 mm lug to lug, and 15 mm thick. It fits wrists from ~17.5 cm (flat-fit estimate).

Sources checked · How we source numbers
Case
42 mm1
Lug to lug
50 mm1
Thickness
15 mm1
Lug width
not published by Spinnaker
Spinnaker SP-5121-AA: size drawingSpinnaker SP-5121-AA, round case, top and side view to scale: case diameter 42 mm, lug to lug 50 mm, lug width — (unknown), thickness 15 mm. Bezel, dial and crown size are schematic.lug width —Ø 42lug to lug 50TOPthickness 15SIDE
Spinnaker SP-5121-AA, top and side, to scaleDrawing from data, not a photo · mm

Spinnaker SP-5121-AA specifications

Case diameter
42 mm1
Lug to lug
50 mm1
Thickness
15 mm1
Lug width
not published by Spinnaker
Crystal
Sapphire Lens with Anti-Reflective Coating1
Water resistance
18 ATM1
Movement
TMI NH341 · automaticTMI NH34 specs
Battery
none: the TMI NH34 is automatic
Years made
start not published
Case code
not in our data yet

On your wrist

The verdict compares the lug to lug with the flat top of your wrist. Balanced from ~17.5 cm, past the edges below ~15.5 cm.

= 6.7 in

At the edge on a 17 cm wrist: the 50 mm lug to lug covers 91% of an estimated 54.8 mm flat top.

Flat top = circumference ÷ 3.1, a community convention, not a measurement of your arm. Compact ≤ 0.75 of the flat top, balanced ≤ 0.89, at the edge ≤ 1. Compare more watches in the watch size calculator.

Spinnaker SP-5121-AA: wrist fitSpinnaker SP-5121-AA on a wrist, top view to scale. lug to lug 50 mm. Wrist 170 mm, estimated flat width 54.8 mm (circumference / 3.1). Ratio 0.91: at the edge.wrist, flat topwrist flat ≈ 54.8lug to lug 50At the edge · 50 / 54.8 = 0.91estimate: wrist 170 / 3.1 = 54.8 flatcompactbalancededgeoverhang0.750.891
Spinnaker SP-5121-AA on a 17 cm wristDrawing from data, not a photo · mm

Actual size on your screen

Calibrate once with a bank card and the drawing shows the Spinnaker SP-5121-AA at 1:1, next to a millimetre ruler.

1:1 · not calibrated: sizes are approximate
Spinnaker SP-5121-AA: size drawingSpinnaker SP-5121-AA, round case, top and side view to scale: case diameter 42 mm, lug to lug 50 mm, lug width — (unknown), thickness 15 mm. Bezel, dial and crown size are schematic.lug width —Ø 42lug to lug 50TOPthickness 15SIDE
Drawing from data, not a photo · mm
01020304050

Spinnaker SP-5121-AA strap size

Spinnaker publishes no lug width for the Spinnaker SP-5121-AA. Measure between the lugs with a caliper before buying a third-party strap.

Attachment: not published in our sources.

Find your strap length in the watch strap size tool, with the Spinnaker SP-5121-AA filled in.

Movement: TMI NH34

The Spinnaker SP-5121-AA runs on the TMI NH34, an automatic movement. 2 other models in our base use it.

Beat rate
21,600 bph2
Jewels
242
Hacking seconds
Yes2
Hand winding
Yes3

Battery

none: the TMI NH34 is automatic

A mechanical watch has no cell to replace; it needs a service instead.

Same size as the Spinnaker SP-5121-AA

The models nearest to the Spinnaker SP-5121-AA in case width and lug to lug, drawn over it to scale; below, every model within 1 mm of its 50 mm.

Size comparison: Spinnaker SP-5121-AA, Dan Henry 1963 GMT Automatic, Seiko SLA077J1, Seiko SLA079J1Top-view outlines to scale on one centre. A Spinnaker SP-5121-AA: Ø 42, L2L 50, lug —, T 15. B Dan Henry 1963 GMT Automatic: Ø 42.5, L2L 50, lug 22, T 13.9 (vs A: Ø +0.5 L2L 0 T −1.1). C Seiko SLA077J1: Ø 42.6, L2L 49.3, lug 20, T 13.4 (vs A: Ø +0.6 L2L −0.7 T −1.6). D Seiko SLA079J1: Ø 42.6, L2L 49.3, lug 20, T 13.4 (vs A: Ø +0.6 L2L −0.7 T −1.6).A Ø 42B Ø 42.5C Ø 42.6D Ø 42.6C L2L 49.3D L2L 49.3A L2L 50B L2L 50A Spinnaker SP-5121-AAØ 42 · L2L 50 · lug — · T 15B Dan Henry 1963 GMT AutomaticØ 42.5 · L2L 50 · lug 22 · T 13.9vs A: Ø +0.5 L2L 0 T −1.1C Seiko SLA077J1Ø 42.6 · L2L 49.3 · lug 20 · T 13.4vs A: Ø +0.6 L2L −0.7 T −1.6D Seiko SLA079J1Ø 42.6 · L2L 49.3 · lug 20 · T 13.4vs A: Ø +0.6 L2L −0.7 T −1.6
A Spinnaker SP-5121-AA and the 3 nearest in size, on one centre, to scaleDrawing from data, not a photo · mm

Nearest in size

  1. ASpinnaker SP-5121-AAthis watch
  2. BDan Henry 1963 GMT AutomaticW +0.5 · L2L same · T −1.1 mm
  3. CSeiko SLA077J1W +0.6 · L2L −0.7 · T −1.6 mm
  4. DSeiko SLA079J1W +0.6 · L2L −0.7 · T −1.6 mm

Differences against A in mm: W case width, L2L lug to lug, T thickness. Nearest by width and length together, from the published sizes.

Same movement: TMI NH34

Spinnaker SP-5121-AA questions

How big is the Spinnaker SP-5121-AA?

The Spinnaker SP-5121-AA measures 42 mm across, 50 mm lug to lug, 15 mm thick.

Will the Spinnaker SP-5121-AA fit a 7-inch wrist?

Balanced: the Spinnaker SP-5121-AA's 50 mm lug to lug takes 87% of the ~57.4 mm flat top of a 7-inch (17.8 cm) wrist. By the same estimate (circumference ÷ 3.1) it sits balanced from about 17.5 cm and overhangs the flat top on wrists under about 15.5 cm.

Does the Spinnaker SP-5121-AA need a battery?

No. The Spinnaker SP-5121-AA has no cell to replace: a wound mainspring drives its automatic TMI NH34.

What movement is in the Spinnaker SP-5121-AA?

The Spinnaker SP-5121-AA runs on the TMI NH34, an automatic movement.

More Spinnaker watches

Sources

Documents checked · Report a wrong number

  1. 1Spinnaker Watches — Orange Blue | Bradner GMT Automatic · html · read
  2. 2Time Module Ltd. — Product Line-Up - Mechanical (NH0&NH3); NH34/NH35/NH36 product blocks · html · read
  3. 3Time Module Ltd. — Technical Guide & Parts Catalogue, Cal.NH3 Series (NH34A/35A/36A/37A/38A/39A) - Automatic Mechanical · pdf · read