I exchanged because pure grudge was corrupted by corrosion. I was saved because genuine could only be purchased with a holder and set. However, since the price is expensive, there are considerable differences with respect to forming from genuine. Although the screw part can be used without any problem, it is better not to expect quality. Personally, it is troubled even if it is sold for tens of thousands of yen after it is made beautiful, and we think that it is enough under present circumstances.