Albins 3rd and 4th Synchro engagement Helical Gears are a great choice for a low budget build. The factory 3rd and 4th gears will need upgraded when torque is in excessive of 350wtq. These replace the OEM 3rd and 4th gears, direct swap in B16 and GSR transmissions. Helical cut for QUIET operation, great for a street cars. The gears are rated at 1000hp+. We recommend the Mfactory 5th gear cuff with this upgrade. This setup is what is found in our stage 3 transmission. Gears comes out of Australia, please allow 8-16 business days.