Kit includes billet case with bearings, seals, and gaskets, billet reed valve with 2 carbon fiber petals, mounting hardware, and engraved block-off plate to cover the old cylinder intake (carburetor now mounts to reed valve on the crankcase). Interior case volume has been reduced compared to regular G230RC cases to increase performance. Gives much more power from low RPM's all the way up to full speed. No cylinder modifications needed - just bolt on and go! For ultimate performance, however, additional gains can be realized with proper cylinder modifications. Compatible with all 2-bolt style RC top ends - fits Zenoah G23LH / G230RC / G260RC engines. Also fits Chung Yang CY23RC / CY26RC / CY27RC / CY29RC / GP290 engines. Note: these cases have been specially designed to allow for proper clearances when used in RC cars. Fits the HPI Baja 5b. Carburetor position is substantially the same as a stock G230RC; as such, this item should be compatible with most large scale vehicles including FG onroad and offroads, Carson, Traxxas, DuraTrax, XTM, etc. Minor modifications may be needed to make this item work in your application.