Lucas's KOTRs (that’s ‘King of the Road’) are neat cylindrical little lights, with a machined alloy body attached to a rubber mounting strap, which stretches around most bars and seatposts without complaint (although aero seatposts may pose some problems). The lights use single LEDs and have integrated batteries.
The front section of the lights containing the LED and battery unthreads as a whole to reveal a standard micro USB socket, for which a cable is supplied. It’s straightforward to remove the whole light from the bike, but we found it most convenient to leave the mounts attached, and simply unscrew the light part for charging. The only niggle is that the thread is quite fine, so you have to reinstall it accurately to avoid damage.
We got these very wet without consequence during tests. At full power, which is more than enough to be seen by, the KOTRs last around three hours, which can be prolonged using the low power or flashing modes. The single LED produces a focused output, although the lens does leak some light sideways, aiding visibility. From a driver’s perspective, the KOTRs are bright enough to draw attention; for unlit roads, more firepower up front is a must.