144 grams of G-Shock.

MT-G is the G-Shock line that swaps resin for metal in the parts you see and touch. On the MTG-M900DA that means a brushed stainless steel bezel with four exposed corner screws, set over a resin shock-absorbing shroud that still does the protecting.

The result weighs 144 grams by Casio’s figure. The GWM530A on this site shares the exact 56.8 x 46 x 16.6mm case and weighs 67. Same footprint, different presence.

Module 3406 drives analogue hands over a digital sub-display. The hands give you the time at a glance; the screen gives you the day, a second time zone, a 1/100-second stopwatch, a 24-hour countdown timer and five daily alarms.

Tough Solar keeps the cell charged from light, and Multi-Band 6 corrects the time from atomic-clock transmitters in the US, the UK, Germany, Japan and China. World time covers 31 zones and 48 cities.

Casio and retailer descriptions for this reference list a stainless steel bracelet with a fold-over clasp. The product image on this page shows a black resin strap. We have not been able to reconcile the two, so we do not tell you which arrives.

If the strap matters to you, and on a 144-gram watch it does, check the photos and the item details on the listing you buy from. Everything else on this page, the dimensions, the module and the ratings, is as Casio publishes it and is not in question.