I bought this product because it used a duct nipper from another manufacturer and it could not cut. It was the first time I saw such a cutting edge, so I replaced it because the cutting edge was wrong, but the item sent in exchange was in the same state so I inquired and that this state is the normal state of this product. I actually tried it and it broke up next time at a rate of several times. Did not cut the duct but make a duct break? . Because it is not very usable, I went to Okura. To be honest, it was better to buy a duct nipper of tougi or Kowa after 5000 yen later.