3 working modes: The solar air pump kit has 3 different modes: high speed, low speed, low speed (10 seconds On / Off) Energy Saving: The air bubble pump absorbs sunlight and transfers solar energy into electricity by panel, environmentally friendly. USB charging: not only can be powered by solar energy, it can also be charged by USB, for bad weather without sunshine. Compact and Portable: Compact size and light weight, easy to carry, especially for outdoor activities such as fishing. Fields of application: Widely used to add oxygen to various aquariums, fish tanks, ponds, ponds.