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Seiko watch · Prospex · automatic

Seiko SRPB51

The Seiko SRPB51 measures 43.8 mm across and 13.4 mm thick, with 22 mm lugs.

Sources checked · How we source numbers
Case
43.8 mm1
Lug to lug
not published by Seiko
Thickness
13.4 mm1
Lug width
22 mm1
Seiko SRPB51: size drawingSeiko SRPB51, round case, top and side view to scale: case diameter 43.8 mm, lug to lug — (unknown), lug width 22 mm, thickness 13.4 mm, rotating bezel. Bezel, dial and crown size are schematic.lug width 22Ø 43.8lug to lug —TOPthickness 13.4SIDE
Seiko SRPB51, top and side, to scaleDrawing from data, not a photo · mm

Seiko SRPB51 specifications

Case diameter
43.8 mm1
Lug to lug
not published by Seiko
Thickness
13.4 mm1
Lug width
22 mm122 mm watches
Crystal
Hardlex1
Water resistance
200 m1
Movement
Seiko 4R351 · automaticSeiko 4R35 specs
Battery
none: the Seiko 4R35 is automatic
Years made
start not published
Case code
not in our data yet
Bezel
unidirectional rotating1
Line
Prospex1

On your wrist

No lug-to-lug or case length is published for the Seiko SRPB51, so there is no fit verdict yet.

Actual size on your screen

Calibrate once with a bank card and the drawing shows the Seiko SRPB51 at 1:1, next to a millimetre ruler.

1:1 · not calibrated: sizes are approximate
Seiko SRPB51: size drawingSeiko SRPB51, round case, top and side view to scale: case diameter 43.8 mm, lug to lug — (unknown), lug width 22 mm, thickness 13.4 mm, rotating bezel. Bezel, dial and crown size are schematic.lug width 22Ø 43.8lug to lug —TOPthickness 13.4SIDE
Drawing from data, not a photo · mm
01020304050

Seiko SRPB51 strap size

Lug width 22 mm1: a 22 mm strap with 22 mm spring bars fits between the lugs. 45 other models take 22 mm.

Attachment: not published in our sources.

Find your strap length in the watch strap size tool, with the Seiko SRPB51 filled in.

On a bracelet? How to remove watch links to size it to your wrist.

22 mm strap: strap diagramTwo-piece strap laid flat (22 mm strap). Lug width 22 mm. Short piece — (unknown), long piece — (unknown). Buckle, keepers and holes are schematic.short —long —lug 22lug 22strap length —22 mm strap
22 mm at the lugs; lengths depend on your wristDrawing from data, not a photo · mm

Movement: Seiko 4R35

The Seiko SRPB51 runs on the Seiko 4R35, an automatic movement. 25 other models in our base use it.

Beat rate
21,600 bph2
Power reserve
41 h2
2 sources disagree; show every value
  • manufacturer 41 h2
  • secondary source 40, 41 h4
Jewels
232
2 sources disagree; show every value
  • manufacturer 232
  • secondary source 23, 244
Accuracy
−35 to +45 s/day3
Hacking seconds
Yes2
Hand winding
Yes2

Battery

none: the Seiko 4R35 is automatic

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

Same size as the Seiko SRPB51

Same movement: Seiko 4R35

All 26 models on the Seiko 4R35

Seiko SRPB51 questions

Does the Seiko SRPB51 need a battery?

No. The Seiko SRPB51 has no cell to replace: a wound mainspring drives its automatic Seiko 4R35.

What movement is in the Seiko SRPB51?

The Seiko SRPB51 runs on the Seiko 4R35, an automatic movement.

What strap size does the Seiko SRPB51 take?

The Seiko SRPB51 measures 22 mm between the lugs, so it takes a 22 mm strap with 22 mm spring bars. 45 other models in our base share that width.

Find the strap length for your wrist and the Seiko SRPB51 in the watch strap size tool.

More Seiko watches

Sources

Documents checked · Report a wrong number

  1. 1Seiko Watch Corporation — SRPB51 product page (Prospex), seikowatches.com ph-en · html · read
  2. 2Seiko Watch Corporation — Instructions: Seiko Automatic Diver's Watch Cal. 4R15/4R16/4R35/4R36/7S26/7S35/7S36 (English) · pdf · read
  3. 3Seiko Watch Corporation — Instructions: Diver's Watch for Air Diving, Cal. 4R35 / 4R36 (English) · pdf · read
  4. 4Grail Watch — Grail Watch Reference: Seiko Cal. 4R35 · html · read
  5. 5Seiko Watch Corporation — Instructions: Mechanical watch, Cal. 4R35 / 4R36 / 4R37 / 4R38 / 4R71 / 4R72 / 4R39 (English) · pdf · read