The c1 chainring is a full featured crank based power meter that features dual sided measurement total power is recorded by the powermeter but leftright leg power is estimated similar to other power recording chainsets the fsa made one piece chainring design provides added stiffness for shifting no matter the terrain available 5339 5236 and 5036 chainring tooth options for 5 bolt 110 bcd cranks the c1 mounts to existing hardware on the bike additionally dual band ant and bluetoo