This is a set of a Cleansui direct-connect water purifier body and two unopened cartridges! The main unit has been used for 3 months, so please refrain from purchasing if you are concerned! The button battery is still inside and has plenty of capacity remaining. It was convenient because the screen shows how many liters (of water) the cartridge can still be used for. The cartridges, on the other hand, are new and unopened, so they are in good condition! I will provide two of these! I am selling this because I moved and unfortunately, my new faucet has an inner ring type and I couldn't install it. It could be used if your faucet is the type where you can unscrew the ring (or something?) from the outside of the faucet. - Brand: Cleansui - Model: MDC01SZ-AZ - Contents: 1 main unit + 2 cartridges (unopened) - Compatible models: MD series compatible (MD101, MD201, MD301, MD311) - How to use: Direct-connect water purifier