This CI Humification unit is a convenient little 2oz jar of 50/50 activator beads. Add distilled water and watch the crystals quickly absorb it, expanding to fill the entire jar. The 50/50 solution of propylene glycol will slowly release moisture as needed to maintain a relative humidity of 65-70% inside your humidor. And refilling is just as simple. Once the beads shrink to their original form, add more distilled water. Easy!