playing around with my new Ultrafire WF-500 I noticed the threads on the tailcap looked similar to the ones on the Eastward YJ U2-style flashlight. So I tried lego-ing the reverse clicky of the EYJ on the WF-500 and ... voila, it fits.

Without thinking too much I pressed for on... still working... the second stage however didn't work, the switch functioned on-off-off... When I put the EYJ back together I noticed the dim stage of the tailcap was really really dim now... the led barely glowed. I guess the current from the WF500 fried the resistor. After a little soldering (inserting a new resistor) it functions properly again... whew.

Could anyone check for the original value of the resistor in the EYJ tailcap? I have 10 ohms in there now, but that seems a little dimmer then I recall it to be originally.