Powered by 2-2016 Lithium coin cell batteries, the RadiantA(R) Microlight 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 Microlight also features four lighting functions and a water-and-crush-resistant body, plus a stainless-steel universal clip that attaches easily to keys, zippers, purses, backpacks, military gear and any number of convenient locations. PRODUCT DETAILS Four modes: High, low, strobe, signal Run time: 22 hours on low Effective range: 50 ft (15.24 m) Signal visibility: 1 mi (1.61 km) Battery type: 2-2016 Lithium batteries included Easy-open/snap-shut construction for effortless battery replacement Temperature operation range: From -4Adeg F / -20Adeg C to +104Adeg F /+40Adeg C Durable stainless-steel universal clip attaches securely and releases easily