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.
The following tags are aliased to this tag: 0.01_condom (learn more).