I call this "Personnas of the Mysteries." So you're about to get my opinion. The tucks available...arrows on the blade...sold as Blues, are really Barber grade. I believe there is a difference between the Blue Labs and the Med Preps, with the Med Preps preferred.
Now, the Blue Labs are coming with arrows on the blade. I use Med Preps so I don't know exactly what is going on. When the factory is called, there seems to be conflicting answers.
The mystery deepens. I like a little mystery in my life.