Boveda 2-Way Humidity Control Kit for Wood Instruments Catalog ID: ACNABVW49K Boveda 2-Way Humidity Control Kit for Wood Instruments makes humidifying your instrument effortless. Patented humidity control packets respond to ambient conditions by adding or removing moisture. This kit is designed to maintain a constant 45-55% humidity level within your instrument's closed case.Each Boveda packet utilizes a specially prepared solution of pure water and natural salts, contained within a water-vapor permeable ''reverse osmosis'' membrane. Packets typically last between 2-5 months; longevity depends on time of year, case quality and ambient RH levels. Replace when packets become rigid.Kit Contains:2x 70 Gram 49% RH Packets1x Leak-resistant Fabric Holder Out of Stock List Price: $27.95 $22.00 Buy Continue Shopping