The smallest, lightest SteriPEN, the SteriPEN Adventurer-Opti, uses a revolutionary optical eye to sense the water. The patent-pending technology ensures safe use and provides water purification in even the coldest of waters. 

The new optical sensor doubles as a convenient LED flashlight. It’s a great backup light when camping or taking a night-time walk to refill your water bottle. The flashlight mode is activated by pressing and holding the single button down for 3 seconds. The clear lamp cover focuses the LED light.

The handheld SteriPEN Adventurer Opti ADO-RP UV water purifier 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).
Specifications:

• Weight: 103g/3.6 oz. with batteries
  
• Size: 15.5cm. (6.1in.) x 3.3cm. (1.5in.) x 2.2cm. (1.0in.)
  
• Battery: Uses two CR123 batteries (included)
  
• Battery life: Disposable – 100 treatments (16oz./0.5L); Rechargeable – 40-50 treatments (16oz./0.5L)
  
• UV Lamp Life: 8,000 treatments 
  
• Travel Case: YES