These solar-powered speakers are similar to old gramophones’ horn and their name – Gramo – comes from here. The speakers are covered with three layers of photovoltaic panels. Additionally, they can be used with computers, notebooks, iPods, and iPhones. So, if you decide to have a party at beach, these speakers will be a great solution. Moreover, it has an internal built-in battery pack which gathers sun power during daytime and enables to listen to music even after the sunset. Also you can change the volume range using soft-touch controls on the speakers.