This is a one step above stock Nitrited low friction valve for the Ecotec 2.0 LSJ/LNF/LHU/LDK, and the 2.4 LE5s. These valves are .5mm oversized, we have tested many valve sizes and this is the size that we recommend. The head needs to be ported to take full advantage of an oversized valve. Installing a full set of these with no other modifications will increase the compression ratio on an LNF from 9.2 to 9.3 and an LSJ from 9.5 to 9.75.
The next upgrade above these are the Inconel valves.