Add one to any box of cigars or travel humidor and you have instant cigar humidor. Fits easily in a box of cigars after one stick has been removed. This item works using a "micro-sponge" inside a vented tube. Simply place the unit under running water ( distilled if you prefer) , shake off the excess place in box and close lid. Once the sponge has evaporated its water refill again and re-insert! Its easy and quick! Keep cigars fresh for trips, camping, golfing, or any kind of reason!