This is a two-pronged attachment comb for manual clippers. It's a part for adjusting the length, rather than a replacement blade. It's a set of 5, and the size is indicated as 10x12. The actual size is about 5 cm x 4.7 cm. Since it's from that time, there is some aging. Therefore, although it's unused, it's listed as having some dirt. Please refrain from purchasing if you are concerned. I will ship it with the box. Currently, manual clippers are not very common, so the parts themselves are rare. It could also be a part of a Showa retro collection.