The Ultra Doppler is USB rechargeable saving money while reducing your footprint.Ultra Doppler Tail Light Specifications.

Rear

• 3 super bright LED's producing 7 Lumen's
• 4-Modes
• 3 Strobe patterns – 12 Hour burn time
• Steady on – 9 Hour burn time
• Cable free integrated USB 2.0 charging
• 180° Side visibility
• IPX3 Waterproof rating
• Quick release, multi-mount silicone body
• Red low battery indicator
• Green fully charged battery indicator
• 2 Hr charging time
• Fits all bar and seatpost diameters
• Black body, red lens
• 40 grams

Front

• 38 Lumen super bright LED
• 3-Modes
• High – 5 Hour burn time
• Medium – 9 Hour burn time
• Flash – 9 Hour burn time
• Cable free integrated USB 2.0 charging
• 180° Side visibility
• IPX3 Waterproof rating
• Quick release, multi-mount silicone body
• Red low battery indicator
• Green fully charged battery indicator
• 2 Hr charging time
• Fits all bar and seatpost diameters
• Black body, clear lens