C4 LED technology, impervious to shock with a 50,000 hour lifetime. 120 lumens measured system output, 6,800 candela peak beam intensity, and 165 meter beam distance, runs 11 hours. Three "AA" alkaline batteries (included)| Push-button on/off switch easy to use even when wearing heavy gloves. One meter impact-resistance tested. Package includes both elastic head strap and rubber hard hat strap. Intrinsically safe Ö Class I, Division 1| L x W x D: 1.88" x 2.5" x 3.08". 7.1 oz (202 g)... Tools and Hardware.