Details:

Advantage 70 Humidified Tubes are precision devices designed to maintain the optimum relative humidity of 70% within the tube.
Ad70 Tubes maintain cigars just like the finest desktop humidors.
The humidification element in the cap of the Ad70 is initially charged with a starter solution available at most tobacco shops.
Subsequent refills can be made with distilled water.
The element and solution maintain optimum humidity of 70%.
Ad70 tubes maintain fresh cigars, and can often restore dry cigars.
Please note that stale cigars, whose essential oils have dried out can be rehumidified, but will not smoke well as when they were fresh.
However, if a cigar is a bit dry, but not stale, a few days in an Advantage 70 Humidified tube will renew it quite well.