Seiko MM300 SBDX001 Curved End Hexad Watch Bands | Strapcode
Seiko Monster to Sumo to Marine Master - Overview of Seiko Divers - YouTube
Seiko PROSPEX - The Sumo gathering | PHOTO REPORT
SBDX017 & SBDC031] my MM300 and my Poor Man's MM300. Modded a Sumo into a PMMM some 5 years ago and later replaced it with a real one when I could afford