Sort of aquarium related if you want a good light for peering into your tank at night
In order to get UV LEDs for my lighting project I bought several UV flashlights and took the UV LEDS out of them. I swapped in genuine Cree XR-E cool white LEDs putting out 200+ lumens. These are very bright and the LEDs drain the batteries more slowly then halogen bulb flashlights. They take two CR123 batteries.
Four available for only $15 each. Compare that to Cree emitter flashlights at Canadian Tire etc. for $30 or more. One has a gloss finish and the others are more of a satin finish. Not sure why they came with different finishes but that's what was sent to me.
Here's the flashlight illuminating a wall in a completely dark room:
