Vintage Casio W-47 Module 549 Water Resist 50m Alarm Chronogarph Japan | eBay
Casio Watch 549 w-720, Working, with original manual and new battery | eBay
My Casio W-780 [549] c.1987 : r/casio
CASIO EDIFICE - A powerful large dial in dynamic distinguished design provides excellent visibility. The basic functions of EFR-549 with black genuine leather band shapes to be more visual. EFR-549L-1AV http://products.edifice-watches.com/asia-mea/en/_ ...
any idea what module can be retro fitted on this?? it belonged to my grandfather, it's a w73 549 module : r/casio