This is a cartridge for the vapor-type humidifier, Moist Shield. I replaced it last season and used it for only one season. I am selling it because I replaced the model this winter. The replacement目安 (guide) is about 3 seasons (about 12 months), so I think it can still be used. In addition, it is currently sold separately at通販生活 (Tsūhan Seikatsu) for 2,750 yen (tax included) plus 385 yen for shipping. It will be shipped in simple packaging.