Bovedafor Music: Double Fabric Holder - Holds Up to 4 Standard Size 49% RH for Wooden Instruments - Improves Efficiency of Two-Way Humidity Control in Instrument Case

it is what it says it is...but I could have just left the humidifier packs in my case as is. the humidifiers are quality! but this sleeve is single stitched, rough edges thin material - so basic. maybe for a guitar, so the packs aren't sliding around; but for a woodwind case where you tuck it into a nook, there's absolutely no need for this.

Much better designed holder and humidity packs are much better value

I have been using Boveda 49% humidity packs and these double sleeve holders in my acoustic and electric guitars for years. Very easy to use, no mess, very convenient. I have a couple of these holders that are 7 years old and they look like they did when they were new. I see no reason to switch to anything else. Excellent product.

Same as the D’addario brand packets. In fact, this is the company that makes them for D’addario.

Easy to install within my guitar case and a good value as the neck on the acoustic guitar is subject to warping. Nice to use with my electric guitar to prevent humidity changes.