These LED Finger Lights have four functions; High Power, Low Power, Strobe, and Signal Mode. Comfortable adjustable finger strap allows you to easily direct the light where you need it.  Powered by 2-2016 Lithium coin cell batteries (included), light is an ingenious micro LED flashlight, with a surprisingly powerful performance—it has an effective range of up to a 50-feet, and one-mile signal visibility. The light also features four lighting functions and a water-and-crush-resistant body. 

•Four Functions – High Power, Low Power, Strobe and Signal Mode
•Run Time (up to): 22 hours
•Effective Range (up to): 50 ft (15.24 m)
•Signal Visibility (up to): 1 mi (1.61 km)
•Battery Type: 2-2016 Lithium batteries included
•Easy-Open/Snap-shut construction for effortless battery replacement
•LED Colors Available: White, Blue, Green, Red.
• Black (Light emits only from LED)
•Dimensions (Length x Width x Diameter): 1.85"H x 1"W x .325"D