The custom cardboard boombox is made of 350g art paper, and it an Eco - friendly folding speaker which is compact, portable in size and extremely lightweight. There are no batteries or external power sources required, and it is compatible with iPhone, iPod, MP3 players, computers and any other devices with a 3.5mm audio jack. Full-size sublimation printing on this promotional paper speakers allows you to spread out your branding to maximum levels. It is ideal for use on any occasions where you want to bring your music.