Another 18650 flashlight available here

The 18650 advantage

"18650 is the most economical lithium-ion battery in terms of cost-to-energy ratio is the cylindrical 18650 (18 is the diameter and 650 the length in mm). This cell is used for mobile computing and other applications that do not demand ultra-thin geometry. If a slim pack is required, the prismatic lithium-ion cell is the best choice. These cells come at a higher cost in terms of stored energy." -from google.com

Power source
1 x 18650 3.6V batteries (Sold separately) 

Material: Aluminum alloy body
Brightness estimation: 130 lumens

Models shipped prior to August 10:
You can use either 3.0V CR123A batteries or 3.6V CR123A batteries on it, but it is ideal for 3.6VCR123A batteries.

Models shipped after (and including) August 10:
(UPDATE) Use only 3.6V 18650 batteries on this unit, using CR123A may shorten the life of the bulb on this flashlight.

Length: 5.51
Height: 1.38
Width: 1.38
Height: 4.06 oz

Length: 14 cm
Height: 3.5 cm
Width: 3.5 cm
Height: 115 g

Place one Li-ion 3.6V 18650 batteries rechargeable only battery into the flashlight and press the rear button to turn it on. Do not use 3.6V/3.0V CR123A batteries in this flashlight.