Weighting at only 1.45oz with 1 AA battery installed the ZLH501 has a max output of 96 lumens* and can run for 2.3 straight hours. On the lower settings, 18 and 3.3 lumens runs for 19hours and 3.5 days respectively. Takes one AA size; alkaline, 1.5v lithium primary, NiMH rechargeable, or 3.7v 14500 Li-ion rechargeable. Reverse polarity protection built in. Waterproof and aluminum casing.
$59 via zebralight.com
*rate on a 1.5v Sanyo 2700 mAh NiMH battery, imagine the lumens ons a 3.7v Lithium ion battery 