This is the earliest Sadaharu Oh shitajiki that we have ever encountered. A shitajiki is a colorful plastic sheet that is placed between a student's writing paper and school desk, so as not to scratch the desk while the student is writing. From the image and facsimile autograph on the front, we see that this shitajiki dates from early in Sadaharu Oh's career. The back features two rulers, "Giants", Oh's name and position in Japanese at the bottom. We do not know anything about the AAA company that produced the item.
Size: 7 1/8" x 10 1/2"