It is called "Tuna" because it looks like canned tuna.
Very good looking and comes with original rubber strap.
[Condition]
The case and back case is very good condition only with slight marks.
Engrave on back case is remaining clearly.
The crystal has slight mark on 4 but it does not stand out.
The crown screw is available and calendar quick set is also working.
Of course it is original.
Brand: SEIKO
Model: Professional 300m Diver "TUNA"
Ref: 7549-7010
Year: 1980
Movement: Quartz
Case: 47.5mm
Material: Stainless Steel
Strap: 22mm
Includes: Original Rubber Strap