Specification: *Power Source: 2 x CR2032 batteries (included) *Small size,durable and flexible. *Long service life *One button to control 3 mode function: steady on, strobe, slow flash. *Easy to Install: with the flexible loops they can be easily cliped onto tubes from about 5/8 to 1 inch diameter. Application: This light is designed for boat or kayak as navigation light, it can be used as skateboard light,bicycle warning light,pet safety light, they can be used as climbing light, running light and camping light too. Batteries Life: Each led light are powered by 2xCR2032 battery. Notice: To ensure long service life,please do not put it in the water in a long time. Package included: 4 x Led Light (batteries are included)