Foursevens Quark Smart QSL-X Max: 350 lumens for 1.5 hours and min: 1 lumen for 15 days Bluetooth: connect your light to your phone with the Foursevens smart flashlights app Check current battery life and remaining runtime, configure modes, and set proximity alarms via App Body: aircraft-grade aluminum, lens: optical-grade glass, sapphire coating and antireflective coating Includes one CR123A battery