Fuller Tool 320-0100 Insulation Knife - Double Sided

Cuts like butter on all thicknesses of dark-grey foam for soundproofing a recording studio. Will use next week to cut rock wool. Perfect size for various jobs, as it is large, but not unwieldy. Great quality, the display packaging is reusable, which is fine if you are just going to hang it up on a peg when not in use, otherwise, a sheath or hard case would be better for most of us. The handle does have non-slip rubber, but the reversible/symmetrical ergonomics are not the most advanced and comfortable I have ever seen on a knife. Fuller has always made greatly effective, long-lasting tools for eons, and this tool is a steal! It pays for itself with how much time it saves. Just wish there was a good sheath that fit it.

This was a game changer! My husband and I are remodeling an old house that only had insulation in the roof. Before I was using a box cutter and I wasn’t liking my task very much! This knife is a dream. It’s durable, sharp and makes hanging insulation a breeze! It’a great quality for the price! I attached a few pictures and as you can see the small wall, all has to be cut. I knocked it out in no time! I used the large side and it cuts like bread! I won’t say butter, but it does cut straight clean cuts. FYI, I am not an expert in this field, just a lady working on her home with the help of my hubby!

I didn't have a large insulation job, so I didn't want to buy anything too expensive to cut the pieces to size. But I wasn't getting good results tearing or using a utility knife to cut the Rockwool. So I went looking for a better option and found this. It was a huge improvement in the quality of the cuts, my Rockwool pieces were fitting much tighter to the fire blocking and pipes I was fitting the insulation around. Very pleased with the wavy side cut on this Fuller insulation knife for my small job. The blade is fairly stiff and I didn't have any problem getting straight cuts with it.

Good knife to cut insulation , but 11” was a little too long to fit in a my pouch or tool bag . I cut it down to 7” and it much better 👍👍

This is a priceless tool for cutting fiberglass insulation. Due to local codes, I had to space my studs at 12" on center, so i had to cut every single piece of insulation. To all the negative reviews, you're cutting glass, it's not going to last for ever. I sharpened it with a standard kitchen knife sharpener. Once I put it in at about a 30° angle and that sharpened it for good. I didnt need to sharpen it again. I was about half done at the time. I used this to insulate 3200 sq feet. If you're on the fence, go ahead and get it. I would have wasted so much time using a utility knife, and the cuts wouldnt have been straight. Again, to those of you leaving negative reviews, quit whining and hire someone to do it. It's a good product

Two different style cutting edges and each is useful in its own right. I used to trim both contractor installed closed cell, big box store spray foam and 2” thick foam sheets and of the many tools I’ve tried it performs the best. Second is a standard long kitchen bread knife but it doesn’t compare to the ease and versatility of this tool . Highly recommend

I use this to cut flex duct for HVAC. Awesome knife, be careful, very sharp. No sheath. I used the packaging and tape to make one. Super easy cutting all sizes of insulated flex duct..

This knife is impressive, but not at all good for 2" thick foamboard, which is what I needed it for. The blade thickens toward the center of the length, and that keeps it from going easily to enough depth on thick stock. The reviews are mixed on its value for foamboard, so i took a chance. Nope. Not for thick stuff. May be good for 1".