2 LED 3 Modes Bright Solar Energy Power Bike Mountain Bicycle Red LED Tail Rear Light Outdoor Sports Cycling Lamp The use of high-intensity, high light transmittance of special tempered glass and high performance solar ultraviolet radiation-resistant TPT EVA sealing material, laminated together by professional equipment . There's no need to worry about running out of batteries - just 2 hours of charge in the sunshine will give you 4 hours of constant light and 8 hours in flash mode. Add an environmentally-friendly glow to your bike with this solar powered, clamp-on LED tail light which has 4 modes: quick flash, flash and constant.