1 Bike enthusiasts top equipment have a fever was recommended to buy; 2 The 3 America CREE XML T6 LED color temperature of 5000K the highest luminous flux of 2400 lumens designed specifically for cycling and mountaineering lovers. 3 power: the battery pack with capacity of 4400mAh (4 18650) 2 and 2 on design to provide power backed by powerful 4: high current charger charger and a temperature protection overcharge protection short circuit protection intelligent fast charging fully charged automatic stop parameters are as follows: the input: 100~240v AC 50/60Hz; output: 8.4V DC/1.8-2.8A 5 the circuit: IC 3 files dimming. Constant current always is a kind of high brightness no electricity will go out and unlike step-down circuit will slowly go dark. 6 connection line is the use of 3.5mm in diameter very durable the interface is very strong. 7 after the switch: 4 on 1 off green lit: 100-65% power red: red flashing: below 30% 65-30% electric power 8 aluminum alloy vacuum plated with a light reflecting cup 90 degrees angle used for riding. Perfect match! 9 waterproof: IP-6 rain completely free riding. 10 applicable to all bicycles very simple and easy to use. 11 a 360 degree rotating lamp holder assembly and disassembly is more convenient firm let you ride more secure.