Okamoto Condoms is a particular brand of condom sold in Japan by the Okamoto Rubber Corporation. They are sold in cigarette pack sized boxes with a prominent numeric label referring to the thickness of the latex in that particular product. Most commonly seen in fan art are their red-boxed '0.01' or 'Zero One' variety, at 0.01mm thickness (which happens to be their thinnest product). See the listing in the links below for other varieties sold.
