Gemini's four-cell Duo light packs into a convenient size, so the head unit is barely noticeable when it's on your bars or helmet.
The O-ring keeps the head unit in securely in place on rocky descents. The hardcase battery is a bit more awkward to mount, because there are no rub/slip stoppers. A bit of inner tube round either end ﬁxes that though, and this light’s performance is more than worth a bit of makeshift tweaking.
The light itself gives a huge distance punch, and there's even spread through the beam with a gradual fade at the edges, which is less tiring on the trail than high contrast lights.
The relatively narrow beam means helmet mounting is the smart option for technical terrain. The battery’s big enough to run full chat for two to three hours, but power is programmable, which allows you to balance performance and lifespan as you want.
Reliability on all our Gemini test units has been excellent, and you even get a head strap for use when bivvying, camping or trail running and so on. There’s a two-cell battery option for £150, but that’s got half the run time so stick with the four-cell option unless you’re a real weight-watcher.
Gemini Duo 4 Cell beamshot