ALLEXInsulation Knife with Sheath 8" Long Cut, Japanese Stainless Steel, Insulation & Styrofoam Cutter with Blade Case, Serrated Sharp Duct Knife Tool, Made in JAPAN

If you are not using this you're making a mistake. This is the best way to cut mineral wool and other insulation. Doing a van conversion, I used it on mineral wool, fiberglass, and thinsulate. Highly recommended. I understand it also makes a great bread knife, but I never used it in that application.

Great knife for cutting polyurethane foam for a gun case. Previously tried using a hobby knife and thought I'd give this a try - Japanese are well known for the quality and genius of their hand tools. Works perfectly with the fine serrations using a controlled sawing motion. Some challenges with navigating tight turns but definitely better than the hobby knife. Won't buy again because it works so well and I don't need another...

I had a lot of foam boards to cut through. This thing was the most effective tool i tried, and mostly didn't make me want to pull a van gogh while working with styrofoam.

I use this to cut off spray foam in areas where my reciprocal blade couldn't reach. The blade itself is very flexible and allows you to cut with precision.The project of over, however the blade is still sharp, getting a lot of beating

Sharp knife and the extra length was perfect for cutting 4" mattress foam.

Worked good for cutting insulation for the first two rolls. Started getting dull. Had to go back to using scissors.

The knife is nothing special. It’s just a kitchen knife that is serrated.

Never again