Small Sized and Light Weight for Your Helmet: only 6 oz (167 grams) with battery included
Extremely Bright: CREE XM-L2 LED Bulb
Multiple Mode: HI/MED/LO/Strobe/SOS
Mode Memory: The microchip controlled light remembers the mode you were using.
2-in-1 USB Connector: Charging the battery + Turn the battery into an emergency power bank for your smartphones
LED: CREE XM-L2 Battery: Rechargeable Two Cell Li-ion Battery Pack.
Cell Type: 18650.
Capacity: 18.5Wh/4400MAH, Voltage: 8.4V
Charging: USB charging. 2-in-1 USB adapter is shipped in the box. With this adapter you can charge the battery with a USB power source or turn the battery pack into an emergency power bank for smart phones.
Size: (L)46.6 * (W) 27.5 mm
Weight: 50 grams (Light), 117 grams(Battery)
Control: Single Button
Battery Level Indication: The LED on the button indicates the battery level. Green:full, Red: Low
Note: Helmet mount is not available.
I have been using this light mounted on the handlebar of my road bike & the battery mounted on the frame.