This is an old self-winding wristwatch, approximately 58 years old. Functionality has been confirmed. While it appears to keep time well enough for daily use, this is not guaranteed. Please understand this. Crown operation: No issues. Date change is possible by pulling the crown out one step. Adjust the day of the week by turning the hands. You can adjust the hands by moving them back and forth between 9 PM and 1 AM, but this puts a strain on the mechanism, so it is not recommended. Time adjustment is possible by pulling the crown out two steps. The movement is cal. 6206B. Seiko Matic Weekdater. It has 26 jewels, as the cal. 6206A does, so it is likely an improved version (⁠◍⁠•⁠ᴗ⁠•⁠◍⁠)⁠❤ There are scratches on the crystal, case, and dial, so please take a close look at the photos and consider them carefully. The strap is a used Seiko Milanese mesh, slide adjustment type. If you are looking for a discount, please purchase it elsewhere (⁠~⁠￣⁠³⁠￣⁠)⁠~