Weaknesses: Disappears when I'm not looking - popular with the rest of the crew.
Overall: I think it works well at night. Just cup your hand around a torch shining straight into it and it stays bright long enough to take several bearings.
'EXCELLENT IN THE DAY, DIFFICULT TO READ AT NIGHT'
Overall: Needs to sit under light to be charged up for night time use. Excellent in the day but difficult to read at night - vision a little cloudy to get a reading