This is the popular Casio G-SHOCK model "GA-2100-1A1JF" (commonly known as "Casioak"). It features an octagonal bezel design and employs the lightweight and highly durable "Carbon Core Guard Structure." It's an all-black, simple yet impactful watch. It has been used infrequently and is in overall clean condition. While there are no noticeable scratches or stains, please understand that this is a used item before purchasing. Operation has been confirmed and it is working without any problems. *This is a listing for the watch itself only (no box or instruction manual).* Specifications: Model Number: GA-2100-1A1JF Module Number: 5611 Carbon Core Guard Structure 20-bar water resistance (WR 20BAR) Resin band Analog-digital display (analog + digital) Case size: Approximately 48.5 x 45.4 x 11.8mm Weight: Approximately 51g Notes: Please refrain from purchasing if you are concerned about minor scratches, as this is a used item. Returns and exchanges are not accepted to prevent product substitution.