Boveda Humidification System - Large Starter Kit

From the Boveda: Welcome to Boveda maintenance free 2-way humidity control for fretted, bowed and wood woodwind instruments, including: acoustic guitars and basses; guitarróns; violoncellos; double basses; bass clarinets; bassoons; and large cases. Boveda creates the perfect humidity balance for your wood instrument—whatever its surroundings call for. Make any case more protective with Boveda. Includes: 4 Size 70 Boveda 49% RH and 2 double fabric holders.