Dangerous!
I've been sailing all over the Mediterranean for over 20 years. This M anchor in its 20kg version was the main anchor on my newly acquired 12 ton 12 meter boat. I didn't have it for long, because it has already let me down in a ridiculous 20 knots of wind (sandy bottom, chain 16), and this several times at different anchorages. I then used the reserve anchor, a no-name Delta-like product, also 20kg. He always held up without complaint. Conclusion Hands off this Bruce or M anchor, you risk your ship with it very quickly! I threw it into the open sea, I don't want to sell such a dangerous iron to anyone.