Solar 100LED 40ft Warm White Waterproof String Lights by CHOOO 1.FUNCTION - Adds an romantic atmosphere to your surrounding environment. 2.MATERIAL TYPE  Plastic, NI-MH battery. 3.APPLY TO THE ENVIRONMENT - It is suitable for decorating and lighting garden, steps, fence, or outdoor celebration decoration, such as Xmas, wedding, camp, party, festival, etc. 4.SOLAR LIGHTING SENSOR TECHNOLOGY - Built-in rechargeable NI-MH battery,recharge and light up automatically. 5.WATERPROOF:The solar string lights have been tested and certified as IP55 by international authoritative organizations.