Casio · G-Shock · Ref GW-M5610U-1BJF
The square, with the radio and the solar cell.
The classic 5600-shape G-Shock upgraded with Tough Solar charging and Multi-Band 6 atomic timekeeping, rated to 200m. A thin red ring around the display marks the colourway. This is the Japan-market version.
Module readout
01 /
Why the JF matters
The -1BJF suffix marks a reference sold for the Japanese domestic market. It is the same square case idea as the US-market GW-M5610-1, but it is a different reference with its own module, dimensions and packaging, and its own listing behaviour on Amazon.
That is why this page links to a search rather than a single product, and why the case figures are attributed to JDM retailers rather than to Casio’s US site, which does not list this reference at all.
02 /
Module 3495
Module 3495 carries the two upgrades that separate this watch from the DW-5600 it resembles. Tough Solar charges a rechargeable cell from light, so there is no battery to replace. Multi-Band 6 receives an atomic time signal from transmitters in the US, the UK, Germany, Japan and China and corrects the time overnight.
Around those sit world time, a chronograph, a countdown timer, five daily alarms, a perpetual calendar and a power-reserve indicator that tells you how charged the cell is. The LED backlight is the one feature that draws real power.
03 /
12.7mm
JDM retailers list the case at 46.7mm lug to lug, 43.2mm wide and 12.7mm thick, at 52 grams. That is slimmer than the battery-powered DW-5600UBB on this site, and a long way slimmer than the round GWM530A, which shares the solar-atomic idea in a 16.6mm case.
The red ring around the display is the one splash of colour in an otherwise matte black watch. All figures here are as published by Casio’s retailers; we have not measured or timed a unit ourselves.
Specs
- Reference
- GW-M5610U-1BJF
- Case size
- 43.2mm (46.7mm lug-to-lug, 12.7mm thick)
- Movement
- Solar Quartz (Radio-Controlled)
- Caliber type
- Casio Tough Solar Quartz
- Water resistance
- 20 ATM (200m)
- Complications
- Radio-Controlled Atomic Timekeeping, Digital Display
- Origin
- Casio (Japan)
Specifications as published by Casio. We research from manufacturer documentation and published sources rather than hands-on testing. Researched 2026-09-03.
Verdict
The G-Shock square with the battery change and the time-setting removed, in a slimmer case than the base model.
Strengths
- Tough Solar, so no battery to replace
- Multi-Band 6 atomic sync sets the time for you
- 12.7mm thick and 52g per JDM retailers
- Five alarms, world time, perpetual calendar, power indicator
Trade-offs
- A Japan-market reference, so listings and warranty vary
- Case size is retailer-sourced, not yet read from Casio
- Digital only, no analogue hands
- The red ring is a taste call
Buy it if
Someone who loves the square and wants it to run and set itself for years.
Skip it if
You want the US-market reference specifically, or the lowest possible price for the square shape.
FAQ
The U marks the updated GW-M5610U family, which uses module 3495 with Multi-Band 6 atomic sync and Tough Solar in a revised case. It is distinct from the older GW-M5610-1 US reference.
Sources
- Casio G-Shock GW-M5610U-1BJF, Sakurawatches listing
- Casio G-Shock GW-M5610U-1BJF, Haruyama listing
- G-Shock GW-M5610 specifications, G-Central
Researched and last updated 2026-09-03. We do not test watches in hand; every figure above is traceable to the manufacturer or the sources listed here.
Casio G-Shock GW-M5610U
Reference GW-M5610U-1BJF
Prices and availability change; the band above is a research figure, so check the current listing.
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