These are Stainless with hard chrome stems. The only others out there are the ones with the black plating all over. Chrome stainless is the valve of choice for performance applications. That is what we use on our Hayabusa product line. The high end Honda valves used to be available from Manley, but they discontinued motorcycle valves, and they were no longer available.
When the popularity of the sohc 750 dropped off, no one wanted to make them.
We ran into this when we got involved with RC Jr, rebuilding his dads famous bikes, and found that there were no valves available that you could use in those bikes. So we decided to do them again, so the RC fuelers could have valves, and everyone else could once again have a high end valve.
They are hard tip, no lash caps required.