This is a refill tablet for a hypochlorous acid space disinfection and deodorization machine. I accidentally ordered it about two years ago and haven't even taken it out of the bag, so it's new and unopened. It's unopened and has been stored well, so I don't think it has deteriorated based on my experience, but I'm selling it at a lower price because it's been a while. - Model Name: F-ZVC03 - Brand: Panasonic - Compatible Models: F-SMV3000, F-MV3000, F-MV1500, F-MV1000, F-MV4100, F-MV4100V, F-JX1100V, F-MVB11, F-MVB21, F-MVB13, F-MVB10, F-MV150, F-MV300, F-MV200, F-MV400, F-JCT30, F-SM3000, F-MV2300, F-MV4300, F-MV200, F-MV1500 Thank you for viewing. ◻︎Other ・Instant purchase without comment is welcome. ・Please refrain from price negotiations. ・No pets, no smoking. ・No returns or refunds, please.