The Sierra S3 speaker is a high-performance, convenient, and flexible device. Since the solar speaker is charged by solar energy, it features various additional usage options in combination with Bluetooth-compatible devices such as iPod, iPhone, iPad, mobile phones, MP3 Players, PC, notebooks or tablet PCs, and game consoles. Solar Water resistant Wireless Speaker. Very portable, can be used at the beach or on picnics, indoors or outside wherever you want to be. This speaker has the added features of being water resistant therefore can remain outside in the rain or next to you at the beach without the worry of getting it wet as well as solar powered so no need to plug in, just expose the panel to sunlight and it will recharge.