User Manual for Casio Watch Module - MY G-SHOCK News This reference library contains over 1,500 Casio watch manuals. You need to look up the module number of your watch to find the right one. It should be engraved on the case back. Find that number in the list below to view the owner's guide and instructions for that watch. Casio G-Shock Instruction Manuals – G-Central G-Shock Download Casio G-Shock instruction manuals by model and module number in PDF format. For older models not listed visit support.casio to search by module number. For languages other than English visit world.casio. The module number can be found engraved on the back case of the watch. It is the number that has a rectangular outline around it.