Campagnolo's Ultra-Drive cog profiling and beveling is an essential element in the unparalleled shifting precision of the Record gruppo. The high six cogs are made from nickel-plated steel (the nickel plating gives them added durability), and the low 4 cogs are titanium mounted to two lightweight alloy carriers. 188g. Please note that except for the 11/23 ratio, Campagnolo packages their cassettes without locking, and rather supplies them along with their wheelsets. If you're buying a 12/23, 12/25, 13/26, or 13/29 please purchase a lockring if you don't have one already.