UltraFire W878 Cree XM-L T6 800lm 5-Mode White Light Zooming Flashlight - Black (1 x 18650)

Pros: Uses the T6 great white colour & slightly towards the purple end of the spectrum. Even when driven at 3A only marginal gains were had (10-15% approx), so out of the box its a solid performer.

Cons: - Seems to be under driven! - Additional output was definetely produced by bringing the driving current up to 3A (or a little over) I changed the driver to 3x 1050mA drivers (SKU 1885). It does however put out a LOT more heat - I wouldnt drive it 100% continuous. - A slight modification is also beneficial to allow the sliding part to move a bit further forward (boring on a lathe required). - There's no heatsinking from the LED alu plate to the case - should be modified for LED longevity (same as x2000) - body is HUGE & doesnt need to be, could easily be 5mm smaller in diameter as there's a LOT of space around the battery which will need to be packed up

Other: If you need a zoomer - then get it, massive output & very functional zoom. Only fractional improvements (10-15%) can be had from replacing driver. It is 30mm in diameter as a minimum - so could be difficult in some applications.