Boveda 49% Two-Way Humidity Control Replacement Packs for Boveda Starter Kits for Music – 12 Pack – Moisture Absorbers for Instrument Cases – Humidifier Packs – Individually Wrapped Hydration Packets

i originally got these to prevent the neck warping on my acoustic guitars due to seasonal changes. it used to be frustrating to fool with the truss rod every 15-20 days. tried putting this in my hard case as recommended and wow - yes, the neck warping reduced by 80%. I only need to make minor tweaks to the truss rod once in 3 months. But what is even more important : I own 4 luthier built acoustic guitars and each of them sounds extra-ordinary - but only on few days of the year when the weather is ideal ! but now with these humidifiers, these guitars sing at their best every day of the year. keeping ~50% humidity in the case keeps the wood from sounding dry/raspy in summer and from sounding like it has a blocked sinus in rainy season. i think these humidifers are an excellent product to have your precious guitar sounding their best always. u also dont need to waste time on monitoring with a humidifier and add/take out few of the packs, like with other products. these seem to maintain the humidity within a decent range most of the time. yes, buying so many packs a year for 4 guitars quickly adds up to a significant amount of money. but i am not complaining too much about the price of the humidifier packs as it's a good quality,unique product. the only thing i am not happy about is the price of the pack holders. god, these things are just square pieces of cotton and they are sold for obscene prices of Rs 1,500 each ! seriously ? i need 2 of them for each hard case and that for 4 gtrs, just the fabric holder runs upto Rs 12,000. boveda should profit from selling their humidifier and not from fleecing us for tiny pieces of fabric. otherwise, i am happy with this product.