Knog Boomer USB Rechargeable Twinpack Super High Power Headlight/Tailight Combo Set Black Body. Super-bright high-powered 2 contrasting LEDs for high visibility patterning Taillight will produce an astounding 30 lumens of pure Red LED light & Super High Power Headlight Pumps out 55 Lumens of Pure White LED Light ! USB Rechargeable Lithium-lon Polymer with a BURN TIME of 4hrs (constant) 36hrs (strobe flashing) Headlight & Taillight. Plug into any USB port or USB charger. Approximately 2 - 4 hours to full charge ! Headlight Modes 1. Constant 2. Strobe flash 3. Fast flash 4. Random strobe 5. Storage mode ! Taillight Modes 1. Slow Flash 2. Fast Flash 3. Constant ! Each only Weighs 50 grams including batteries ! BATTERY STORAGE SYSTEM To preserve the condition of the Lithium-Ion batteries when the Boomer USB isnt used.