The 800 series or "XX" as they call it at Mat-Mas is the first monofin that Mat-Mas has designed for freediving. So far, they have been mainly involved in manufacturing monofins for pool swimming competitions in Europe. They decided it was time to come up with a product catered exclusively to freedivers.
The "XX" is a mix of carbon fiber and fiber glass, providing the right amount of snap yet not too stiff for deep freediving. After asking Massimo Negrini from Mat-Mas about the mix they use for each fin, he said. "I can’t disclose the exact percentage of each component… It is one of our manufacturing secrets! There is more fiber glass than carbon fibers in the XX, if you want more carbon fiber go for the 900 series."
The XX comes, like any other mononofin from Mat-Mas, in different stiffness, or KSP. The higher the KSP the stiffer the blade. Massimo recommended a KSP 7 or 8 for freediving. The XX comes in European sizing, in 34-37, 38-41, 42-44 and 47-49.
"It is so new that the XX is not even on the Mat-Mas website nor in its 2004 catalog…but soon will be!"