Steri-Pen Adventurer Opti
Description from REI:
New optical sensor doubles as a convenient LED flashlight
Flashlight mode is activated by pressing and holding the single button down for 3 seconds
Clear lamp cover focuses the LED light
Retail package includes 2 non-rechargeable (disposable) CR123 batteries and a neoprene case with belt loop
Device works with containers with minimum 1.75 in. diameter opening (i.e. Nalgene wide-mouth bottles)
Battery life: disposable—100 treatments (16 oz../0.5 liter); rechargeable—40-50 treatments (16 oz../0.5 liter)
UV lamp life: 8,000 treatments
I used it for 50 miles on the AT. I will include the batteries that are already in it. Sells new for $89.95 My price is $50 Shipping include CONUS