Here’s a well thought-out LED rear light with built-in British Standard reflector that runs on two AA batteries – and burn times are very good: in the six months I’ve owned the Cateye TL-AU100, it hasn’t yet used up the first set of batteries.
Given the heavier-than-average weight, the outer case looks very thin to survive being dropped, though time will tell.
Though not as bright as some of its competitors, the level is sufficient for general transport cycling situations and it has a flashing mode. It benefits from a well-controlled beam that delivers bright light towards the rear (at road users behind you), a small amount of light to the sides and just a tiny bit to the top.
The power switch sits neatly in a recess at the back which help to prevent it being hit when the light is inside a bag. And stuffing it in a bag is what you’d have to do when leaving your bike: this piece of kit is a bit big to go into a pocket.
Reliability: 7 / 10
Practicality: 8 / 10
Power efficiency: 10 / 10
Illumination: 8 / 10
Average Score: 8 / 10