This magic magnetoelectric bicycle taillight doesn't need any batteries or solar cell. The faster you ride the bike， the brighter the LED will be.?

Features:
Unique magnetoelectric light， no extra batteries or power needed.
Environmental protection and energy saving.
Tool free installation.
Safe riding.

Specifications:
QTY of LED: 2
Flash: Steady
Color: Red
Material: ABS !#!amp!*! PC
Seatpost size: 18-21mm
Brightness: 10-15LM
NW: 82g / 2.87oz
GW: 90g / 3.2oz
Dimension: 56 * 36 * 28mm / 2.2 * 1.4 * 1.1in
Package Dimension: 85 * 60 * 45mm / 3.35 * 2.36 * 1.02in

Package List:
1 * Bicycle Light?
1 * Seatpost Clamp
1 * Magnet