MagicShine MJ-816U 1900 lumen LED Bike Light with 6.6 Ah battery pack (50% more capacity than the default battery) Light source: CREE XM-L U2 + 2CREE XP-G Luminous flux: 1900LM manufature rated LED lifespan: above 50,000 hours Shell material: 6061-T6 Aluminum alloy Battery: 6.6 Ah BAK battery pack