I bought it because I wanted to do blacksmithing work in the future and to determine the hardness of cheap stainless steel blades at home, which is not enough for durability. Since the width of the velcro that covers the case is narrow, it may open and drop when you carry it. I was a little worried. Therefore, I store it in the paper box that contains the case at the time of purchase, but since the thickness of the velcro is so thick that it is difficult to put it in, I thought that this is the neck if I dare to use it every day, the hardness check body I have no complaints about it.
(Translated by machine.)

I think that it is a must-have checker when judging whether or not the privater can cut the material that I received and whose identity is unknown. You can reduce the risk of the blade being chipped or worn, and it is also useful for determining quenching after making your own blade. Conversely, it can also be used to determine whether a hardened product can be annealed and scraped. I thought it was expensive at first, but it would save time and money.
(Translated by machine.)