I'm not very familiar with Kinnikuman erasers, so I don't know what era they're from. This one was found at home. It's a mini-sized Chibi Keshi, smaller than the regular type. (Image 6 is a comparison image.) There's an engraving on the back, so I believe it's an official one. It's blue, so I think it might be relatively rare. To the untrained eye, I don't see any particularly noticeable scratches, but please check the images to confirm the condition and make your purchase only if you are satisfied! This is a used item.