1. Waterproof . 2.LED light source . 3.Using two 18650 li-ion batteries . Li-ion Headlamp (XD-828):1.It is fitted charge lithium battery, casting off the wire chain .2. built-in 3.7v/800mAh battery.3. Freely adjust light angle, self lock.4.the continue lighting time:8hours.5.suitable: working in evening, study and field trip, camping. Led headlamp XD-828