This dimmable head lamp of LedLenser (serie iSEO) is (Alkaline) is a good choice, equipped with a powerfull lamp and cheap on batteries. When dimmed the burning time is 40 hours (45Lm) LedLenser is a Zweibrüder brand. They manufacture a wide range of torches, headlamps and diving lamps featuring the latest LED technology as well as, in most cases, the Advanced Focus System, one of the best focusing systems available.