Rockwool RXCB11224, ComfortBoard 80 R-6.3 Rigid Stone Wool Insulation Board, 1.5" x 24" x 48", Covers 48 sq. feet, Fire Resistant

Amazon has been very inconsistent in stocking this and the last time I ordered it, they shipped me a box with three rolls of Hallmark brand wrapping paper in it instead of the insulation. But, with that said, it's an excellent product. This is not to be used in walls as batt insulation would be, but rather it's meant to be used on the outside of the air barrier (pressure boundary) to manage thermal bridging and the temperature of the drainage plane (a.k.a. housewrap or whatever). It's far sturdier than regular comfortbatts and far more environmentally friendly than rigid foam!

Very good product! Very easy to cut and install. Fit very well into my generator shed build. I love the sturdiness. Alittle in the high side as far as cost, but required the heat rating for insulation for a high heat environment!

It’s great stuff Good for insulating basement specially

I have a roof mounted ac condenser. I used this in the attic, on the inner side of the roof, directly under the ac unit. It quieted the hum by about 50%. Which was aabout what I expected. Rockwool makes a sound batt also, but I could not find it near me. I am happy with the results. Easy to cut using only a serrated knife blade.

Can’t find at big box stores thanks

Goggles, a special high filtration mask, a hazmat suit, just to work with this stuff it's too much bother to work with. You're supposed to wear the stuff even to carry it around, seriously, I'm sure they didn't warn the post man and it wasn't entirely wrapped up and covered in plastic when it was delivered. I got some in my eye and it's still bothering me weeks later. I would not have bought this stuff if I had known what a pain it is to work with.

Material was.a little damaged but still usable.

Pricey but works well