PL-SLM(R): Solar Bicycle Taillight with Three Red LED (Rear) Light weight: Portable light weights only 80g. Eco-Friendly: Using renewable solar power to light up, decrease pollution from mercury and other chemicals. It is quality with environment in mind: ROHS compliant and CE certificated. Lasting: Sturdy, water-resistant, elegant hard housing protects the headlights innards against the bump and crush, good for cycling in any weather condition. Effectiveness: 2 hours quick charge under sun. It works for 12 hours for constant mode or 20 hours for flashing mode in full power condition. Hassle-free: Quick Installation with hassle-free adjustment.