Elga Labwater Twin-pack Cartridge Unit EA. The cotton swab method offers the advantage of knowing exactly what is in the bag before opening and eliminating the chance of contamination from foreign particles. The cartridges are filled with clean water from a sacrificial source such as a municipal water supply or a private sewage system. After use the absorbency layer returns to its original state and the bath is ready for use. The second layer of absorbency makes it possible to determine the correct volume of water to put in the bath. When using the cotton swab method use the double layer of paper towel between the absorbent pad and the cotton swab. Place the paper towel between the paper towel and the absorbent pad and let the paper absorb the water. Washing the absorbent pad after each use with soap and water usually completes the purification process. Specifications for Elga Labwater Twin-pack Cartridge LC141: Catalog number: 89204-308 Type: INST/EQUIP 0-499 Description: Twin Pack Cartridge Supplier No.: LC141 Package Contents: Elga Labwater Twin-pack Cartridge LC141 / 89204-308 The Elga Labwater Twin-pack Cartridge LC141 is a quality addition to the Elga Labwater lineup. For more great deals on Laboratory Apparatus by Elga Labwater please browse our Elga Labwater Laboratory Apparatus page. Elga Labwater Twin-pack Cartridge LC141 Unit EA