I've just bought one today. The packaging says 180 lumens and beam length 170m. How accurate that is in the real world I don't know but I've just taken it outside to try it out and its staggeringly bright, like a car headlight. Too bright to use in a tent on full power but it has a half power mode which is probably bright enough for most use and should save on battery juice.
It feels pretty robust so I'd say well worth a punt at £8.