Dear Casio-San I remember and still have my DW-5600C from 1988. I also have DW-5030C and DW-5030, with 3229 module anniversary models. I am a regular contrubutor to G-Shock forums and enthusiast for over 30 years! My recommendation is that you keep module 3229 the same but add a dual time feature to module 3229 as you did with the DW-5600C. How would you benefit from this economically? 5600E for example is your biggest seller worldwide. Enthusiasts are crying out for the simple feature of adding dual time (with current time displayed in that mode like DW-5600c had). Sure the new 5000 has world time, but it is awkward to operate and not displayed in current time mode(s). You are doing yourslef a diservice by not adding a simple dual time tp module 3229. I request you do shortly. Thanks for considering his free advice. M. Vas, Australia. Email: [protected]@outlook.com