This is a good solid hole saw. It's not designed for metal, but works well with chipboard. Bonus, it comes with its own mandrel, a spare bit, and a hex wrench for changing the bit.
High quality. Works perfectly. BUT it is NOT 6 1/4 inches. It's only 6 3/32 inches. Not a huge difference, but if for some reason you buy a 6 1/4, expect to get a 6 1/4. It won't work as intended, but I can use it for other projects. Incorrect description information needs to be corrected if they want 5 stars.