Rechargeable: The black l13uv lamp can be recharged with the supplied USB charging cable without an additional battery. When fully charged, it lasts about 2.5-3 hours on high load and about 7-8 hours on low load. Additionally, we provide a battery holder that holds 3 AAA batteries. Looking for invisible stains: This black flashlight emits wavelengths of 390 to 395 nanometers to help detect invisible food and urine stains on carpets, rugs and clothing. Extensive use: the black flashlight can also be used to certify coins and official documents such as driver's license or to identify unwanted bleaching agents in cosmetics, as well as for external uses such as the search for scorpions and minerals. High quality: This UV flashlight is made from aircraft grade aluminum alloy housing with hard anodizing, water and shock resistant and durable. 12 UV LEDs have a lifespan of 100,000 hours. Warranty and service: 100% Satisfaction guaranteed! We will provide you with a satisfactory solution within 24 hours! Provide quality customer service. If there is any problem with the L13 UV flashlight, please refund or replace it.