This slim, flexible rubber tube fits right in your case to protect your instrument from dryness. It is used to regulate excess moisture or overly dry conditions simply and efficiently.
If you live in an arid area, or for dry winter conditions, soak the tube in regular tap water and leave in your case (not in one of the joints). It maintains an even, correct amount of humidity in the case to protect your instrument from cracking and drying out.
If you live in a high humidity area such as an island, or by the seashore, put the tube in your case dry. It will absorb and hold excess moisture, allowing you to avoid rot and mildew from overly moist conditions.
A small active humidity chart to monitor the amount of humidity in your case is included. Made by the Dampit Company. The rubber body is 13″ in length. The absorbent interior wick will last for years.