Add water and it will light up without the need for batteries or charging Just adds water / salt waters and shake it to generate electricity and light up Compact in size and light weight, it can easily fit into backpacks and emergencies bags, making it to carry and store for outdoor camping, hiking and exploration Adopting low-power LED light source, it not only saves electricity but also provides sufficient brightness, suitable for use in tents and enclosed spaces Waterproof design, can work normally even in humid environments, and can be used for outdoor, rainy, and water related scenarios Adding water once can provide up to 120 hours of lighting, meeting the emergencies lighting needs for long term outdoor camping, disaster