This is a 3-pack of Cleansui water purifier cartridges, model MDC01SZ-AZ. Compatible with the MONO series. - Brand: Cleansui - Model: MDC01SZ-AZ - Quantity: 3 cartridges - Compatible Models: MONO series - Other Compatible Models: MD111, MD201, MD101, MD301i, MD301, MD102, MD103. Please refer to the box photo for other compatible models. I purchased and stored these, but they are no longer needed at my new residence. The cardboard box was opened for photography only, and the inner plastic bags containing the cartridges are unopened and brand new. I am open to price negotiations depending on the situation, so please feel free to contact me.