The wrap is easy to cut with a sharp (must be sharp) cutter. When I went under the house (where the ducts are located) I would feel AC coldness in the summer and heat in the winter. I had previously sealed any air leaks in the ducting with caulk and would still feel the cold or hot when under the house. Since I put this insulation up I have noticed a reduction in the ambient temperature under the house vs before the insulation. I simply laid the insulation on the top of the flat main branch of the duct system and taped it to the sides as well.

I got this to use for wrapping my water pipes against freezing, the rolled narrow width pipe insulation is a pain to work with but with this I'm cutting it by unrolling just enough to cut across the roll side to side into about 4"x15" strips and wrapping the pipe so that the 15" is lengthwise along the pipe and the 4" is wrapped around, secure it to pipe with 2 or 3 small pieces of the aluminum tape to hold, then 3 more strips to hold it after you wrap it around to meet together slightly overwrapped, then use one long 15" strip of the aluminum tape to seal that over lapped edge against moisture and mice who love the insulation. It's much easier to wrap pipes this way, more economical imo and looks neat when done, also the foil backing on this is thicker than the rolled stuff, much thicker! I'm also thinking of using this to repair the damage done by rats to my engine hood insulation mainly due to the thickness of the aluminum, I had used some from the online auto store JCW prior to getting this and the aluminum on that was pathetically thin in comparison. Whether you plan on wrapping ducts or using it for other things where you need insulation, you will be happy with this product. PS, a reviewer talked about the plastic sheeting running out, I don't think it's meant to be used as it comes off easily and as he said doesn't run the entire length, I don't think it's a vapor barrier cause any of the rolled pipe insulation I've used in the past doesn't have that and this is stuck to the aluminum side not the material.

Easy to work with and no itch. Not sure why it is listed as 1" thick though as it is closer to 1/4. Get yourself scissors if you are cutting to shape as a utility knife won't cut through cleanly. Pairs well with aluminum HVAC tape.

Worked well for my application. Wanted to insulate a metal vent opening in the attic and seems to have worked. Easy to work with .

I used this in cat shelters for the neighborhood cats. They prefer the houses with this insulation and it seems very warm inside.

Easy to work with, and not messy. This review is to note that to wrap a 6" diameter metal flex duct takes about a 24" length of material, more than I thought (pi x 6 = 18). I used this to wrap the flex duct that leads to my basement office, and even though I only wrapped about 3/4 of the run, I notice the difference in heating right away. We are -15 F in Wisconsin right now!

Great insulation perfect for your air conditioning ducts

TL;DR: Product comes very compressed to about 1/4 inch thickness out of the box reducing its effectiveness. It needs to be "fluffed" with some time and effort by you, the customer, to achieve the R Value of 4 at 1 inch of thickness (what the specs are listed as).

My biggest problem with this product is, as others have mentioned, the thickness the insulation comes in out of the packaging. Because it arrives in a tightly wrapped roll, when taken out of the packaging and laid out flat, the thickness of the insulation averages about 1/4 inch. The packaging lists the thickness as "1 inch", but clearly it is not.

Why should you care? The effective "R Value" of the insulation decreases (it becomes a less efficient insulator) as the material is compressed. So you're not getting the full insulating performance of this material the way it comes out of the package, and the packaging makes no mention of needing to "fluff" out this stuff. I doubt it would fluff up enough over time on its own to reach the stated specs, but I don't know for certain.

So how can this be fixed? Here's what I did:

1. Turn on some mindless television and get comfy

2. Take the product out of the packaging, roll it so you can work on it while you're parked on the couch

3. The insulation seems to be made up of a thicker bottom layer / sheet attached to the reflective material, a matching top layer, and sandwiched between the two is a looser weave of insulation that can be expanded with some effort. Go around ALL the edges of the piece you're working with while gently (and slowly) pulling up on that top thicker layer / sheet of insulation. Pinching that top layer and pulling up softly worked well for me. The sandwiched section being expanded kind of looks like a small stretchy elastic accordion while you're doing that, pretty satisfying in weird way.

4. Once you've got all the edges fluffed out, work your way down the roll pinching and fluffing the top layer again, but this time focus on the middle of the product so that the middle is about the same thickness as the edges you just fluffed. In this step, you're trying to get a generally uniform thickness in the middle of the product to match the edges. I just found it's easier to do the edges first.

5. Repeat steps 3 and 4 until it's as thick as you want it or can get it. This isn't a fast process, but it's oddly enjoyable. This is essentially cotton insulation, so it's safe (and weirdly fun) to touch.

6. Admire your thicc work

Wonderful product that is easy to install and works great for tight spots when insulating a camper MiniVan. Very impressed with this product and would recommend it for sure.

I have two different types of heating pipes, and I used this product for 2" pipes. It does a good job and insulates the pipe very well. The only problem is, I had to use lots of rolls and cost me more compared to the foams for 1" pipes.

great product, fast service, easy to install.

It does what it’s suppose to do, wrap pipe and keep it insulated

As others have mentioned, it's not 1" thick, it's maybe 1cm thick. But there's no way I was going to work with fiberglass above my head.

I used it to insulate furnace duct vents in an undeveloped basement area. It was easy to install with foil tape, and no itching. The insulation is decent, and the bedrooms are now warmer. Price could be better considering how thin it is but overall I am happy with it.