This is the brass gear kit for 13Metanium, 15Metanium DC and 16Metanium MGL reels. Gears are micro-module brass gears from Shimano. Stock main gears of these models are made of duralumin, which is not as durable as brass. You may change gear ratio to any of 6.2, 7.4 and 8.5. Comes with drive gear, pinion gear and a carbon drag washer. Drive gears and washers are from Shimano 19 Scorpion MGL. Pinion is that of Shimano 16 Metanium.