I know this drop-in is proprietary to the head..you cannot swap the drop-in for another p60..you could however do an emitter and driver swap if you wanted to mod..
You could stick the head on any Solraforce body, and Ultrafire WF-504B (old style) an Uniquefire L2, and probably the SkyRay/equivalent/Seraph clone though I'd not bet on the last one. If it fits on an L2i body it'll fit on any other Solarforce body - even an L2r if you are mad enough to try that.
Hint:
It won't work with an L2r.
But an emitter/driver swap will involve soldering.
Basically there’s an l2i and an l2p version. And like others have said needs a swap to upgrade. I still want one for the bigger than p60 head but I just got a trustfire Mrv clone XML from MF which should satisfy that desire.