This set carries an R5 designation in the Japanese Baseball Card Checklist & Price Guide, Vintage Edition 2.1, meaning that five or fewer copies of this card are known, thus making this an exceedingly rare card of Sadaharu Oh. JRM 39b cards are slightly smaller than JRM 39a cards. The text printed at the top of the card back is "Giants Furikake". This card was most likely a promotion for a product from the mid 1960s. Furikake is a condiment meant to be sprinkled on top of rice.
Size: 1 1/16" in diameter.