Replacement full size water cartridge for the Cigar Oasis XL and Cigar Oasis Excel models. This water cartridge is 6" L x 2" W x 2.25" H and is not intended for use with the battery pack (see Cigar Oasis Starter Refill Water Cartridge for battery use). Cigar Oasis Water Cartridges that clip on to the control unit contain a foam element with the distilled water and an antifungal agent. The fan in the Control Unit draws air from inside the humidor and passes the air through the foam which is full of water and the air picks up humidity and delivers it to the cigars in the humidor. Water consumption depends on the size of the humidor, how good the humidor seal is and how dry are the cigars when you put them in the humidor. Typically, for a well-sealed humidor of 75-125 cigars that is opened 3-5 times a week, the water cartridge could last as long as 9 to 12 months.