You can use it to listen to music when you are bicycling, working out or have a picnic, camping. It can also be used indoors. You can also charge your smartphones with the S1 with its emergency flashlight function. It can also work as a temporary flashlight, it supports TF/Memory card and FM function. (FM radio will function better when an audio cable is plugged in) It is IPX5 waterproof and dustproof skid.