bernie, don't know if you got my pm, but I've spoken to john, (lighthound) and he's told me the z41 won't work on the u2...due to components and tailcap dimensions. He said he's tried this and the only tailcaps that will interchange are the z59 and z58's. $9.99 is cheap though...I'm sure there is another solution. My pm was a bit long winded, but let me know if you still want a non clicking tailcap and I'm sure that between me, you, and and every other fellow cpfr someone can come up with something. :- ) let me know. steve