I would want to know what specific optic the light contains before I purchase.
Optics designed for Luxeon lights will function with the Cree, but not very well.
The Cree XR-E has a significantly different beam pattern than the Luxeon LEDs.
Optics designed specificaly for the Cree are best, and have started to become more available lately.
They are available from Cree, Carclo, Fraen, Khatod, Ledil.
-BPH