Designed to provide humidity for up to 50 cigars, the Xikar Cigar Bar is activated when you fill it with propylene glycol solution. Once filled, drop it into your humidor and it begins a slow, steady release of constant 70% humidity. The crystals inside the bar will shrink slowly as water evaporates over time. Simply refill the bar with propylene glycol (PG) solution to recharge the humidifier. This compact unit is perfect for your travel case or small humidor.