The LabStrong D00172 High Capacity Two-Bed Hose Straight Nipple Cartridge is an economical way to purify water volumes up to 1.9 liters per minute. The water purification cartridge is suitable for small volume applications such as deionization. The hose straight nipple cartridge is an economical alternative for all laboratories and is simple to install. The cartridge life capacity is indicated by resin color change. The resin color will change from purple to light brown, which indicates that the cartridge is exhausted. LabStrong takes extra care in sealing our water purification cartridges multiple ways, ensuring exceptional quality is maintained throughout the two year shelf life. Each cartridge has fitted sealing plugs/caps placed on both ends and then it is further sealed in a bag ? the combination of which dramatically inhibits drying out of the resin.