Brand new racing camshafts made by Odula for the NC (2006-2014) Miata. When used together with a tune and exhaust manifold, horsepower figures of over 200 are possible. Springs and retainers are not included, please use the genuine (OEM) ones. After installation, shims need to be adjusted by selecting proper OEM shims (size vary depending on vehicle difference). Odula Racing Cams should be ordered at REV9 Autosport https://rev9autosport.com/odula-racing-cam.html as they provide the best service and speed we've seen so far!