Personally, I don't like this style valve extension. I prefer the Tufo style, where you basically replace the valve core with the extension.

never saw those before...kewl...might have to get me a pair

You will need a 60mm for 404s, and John's right, the Tufo extenders work much better and never leak. They only work on Tufos and other tires with removable valve cores (I think Conti does).
b

---

"What's good for me ain't necessarily good for the weak-minded."

I put some on last week. Pretty much the usual, need to use a skinny allen wrench to let air out. No problems connecting the pump to the extender