GD-400MB-1ER review

Casio G-Shock Men’s Watch GD-400MB-1ER Review


G-Shock GD-400MB-1ER  Watch Review Summary

My rating: 8.5/10. Great watch. Value for money, durable watch.

Hello, today I’m doing a GD-400MB-1ER review. This is a great, rather distinctive looking G-Shock watch with this interesting green lighting. As you’d expect it’s an oversized, durable, affordable timepiece from Casio. I hope you enjoy taking a closer look at this watch.

I hope you enjoy this G-Shock GD-400MB-1ER review below.

You may also like my 100 best watches under £500 for men.

GD-400MB-1ER review

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At the bottom of this article, you can find a list of my recommended retailers to purchase this watch from

Watch Review

Dial & Case Design

The green detailing on this watch really makes this model stand out. The digital display is pretty unique with the black and green colouring, it’s not something I’ve personally seen done on a G-Shock watches before. The casing itself is made of stainless steel and features that typical protective resin wrap that gives the watch a high level of protection from shock, vibration, heat, and water.

Type Of Crystal

On the front of the case, we have a protective mineral crystal glass. Mineral glass is extra resistant to scratches and knocks due to being specially hardened. The glass is ideal for a watch that needs to be resistant to shocks and drops as it’s also shatter resistant.

Watch Movement

At the heart of the watch, we have a Japanese quartz movement. These are reliable, accurate, and affordable with an impressive approximate 3 year battery life. For this reason, they’re found in many of Casio’s G-Shock range.

Watch Size

Keeping to the standard we expect from many of the G-Shock watches, this model has a fairly oversized design to it. The watch casing measures 48mm in diameter, with a thickness of 15mm. This makes it a large, chunky watch. Whilst many people love these larger watches, it’s worth noting that they aren’t so suitable for people with smaller wrists.


The strap is made of a comfortable, durable rubber resin. It has a 26mm width and fastens with a typical buckle style clasp.

Extra features

G-Shock are known for their multifunction capabilities and this timepiece is no different. Extra functions of this watch include a world time display, super led light, stopwatch, countdown timer, 5 alarms, world time display, automatic calendar. There’s also a display flasher, that’s a light diode that flashes as soon as an alarm, a countdown-time or the hour signal has been reached.

Water Resistance Rating

The water resistance level of this watch is 200m, this is what you find in many of the G-Shock watches and something I’m always impressed with. A rating of 200m / 20 Bar / 600ft makes this watch suitable for professional marine activity, serious surface water sports and skin diving.


Watch Specifications

  • Band Resin strap, standard length, 26mm width, standard buckle style clasp.
  • Case Stainless steel casing with resin surround, sizing diameter: 48mm and thickness: 15mm.
  • Dial Digital display. The window lens is made of mineral glass, this is specially hardened to be resistant to scratches and knocks.
  • Movement Accurate Japanese Quartz movement.
  • Water Resistant A water resistance of up to 200m / 20 bar.

Watch Advantages

  1. G-Shock watches are known for the excellent durability & toughness
  2. Built for shock resistance
  3. Popular oversized design
  4. Interesting green digital display
  5. Useful display flasher
  6. Multi-function watch with stopwatch, alarms, countdown timer, and world time display and more
  7. Mineral glass offers a good level of scratch & shatter resistance
  8. 200m water resistance rating

Watch Disadvantages 

  1. Being an oversized watch at 48mm this may not be suitable for people with smaller wrists


My Final Thoughts On This G-Shock GD-400MB-1ER Review:

The G-Shock GD-400MB-1ER has a lot of the features you’d expect from a G-Shock watch, yet it remains a little different with its clever use of colour that I really like. It’s got that popular oversized design to it, and is extremely durable and tough. These watches have always been well suited for people with an active outdoor lifestyle.

After looking into the watch design, quality, features, and pricing this watch received an 8.5/10 from us at The Watch Blog.

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Where to buy the GD-400MB-1ER

I like to stick to listing retailers that I’ve actually had experience buying from in the past. Below I’ve listed some of the top places to buy this watch from, check all for the best price. Variations of this model include: GD-400MB-1ER

Buy now at Amazon

Buy at Watch Shop

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