With a Seoul P7 LED and four-cell Lithium Ion battery pack, the LUU was just short of the claimed 900 lumen output at a shade over 840, but that’s still easily bright enough for riding fast on unlit roads.
It comes with three diffusers that ﬁt in front of the main lens enabling the beam pattern to be changed to narrow, medium or wide, though there isn’t really that much between them.
The lamp has three constant light settings (low, medium and high) and three ﬂashing modes (fast, slow and low power). The illuminated blue switch is well sealed, and ﬁts well against the main lamp body.
Our test light came with the additional AA battery holder which you simply screw onto the back of the main lamp body to use if your battery is ﬂat or to turn it into a handy torch.
The run time of just over four hours on full power was impressive; better, though, was just over seven hours on medium power, which was more than enough for most riding needs.