BVMFK-LG Boveda starter kit 4x 70gr 49%, with 2 double holders

? Humidity Control Kit
? Humidifies and dehumidifies the air in the instrument case
? prevents warping, shrinkage and cracking of wooden instruments
? maintains a relative humidity of 40 - 50%
? just put it in your pocket with the instrument in your case
? The large kit is suitable for acoustic guitar, cello, double bass, bassoon, bass clarinet and other instruments

Easy to use:

Just insert the humidifier and the rest will happen by itself! Boveda's unique bags have an osmotic membrane that automatically releases the internal moisture into the environment - at a constant 49% relative humidity. The special feature is that the membrane works in both directions, so that excess moisture can also be reabsorbed. There is no need for refilling at all. If the bag becomes hard and dry, it is simply replaced with a new one.