70% humidity guaranteed for a humidor containing 100 up to 300 cigars. The Credo self- regulated humidification system is based on a physico-chemical process whose molecular mechanisms allow a rigorous water evaporation control The principle is based on the creation of melange of water and tensio-active substances which limits the potential of the evaporation of the water itself. It Works! humidity is tamed and the amateur is carefree. 22 x 8 x 3cm