Philips SBA3020 Wired Portable speaker Dynamic bass boost - hear the deepest, richest bass - Innovative technology delivers unbelievably deep, rich bass from compact speakers. Dynamic bass boost emphasizes the bass content of the music throughout the range of volume settings from low to high  at the touch of a button! Lightweight, portable design for music enjoyment anytime - The durable, lightweight material and design mean you can carry the speakers with you wherever you go. Digital amplifier for interference-free sound - For improved sound performance, these speakers feature a digital amplifier so you can enjoy the sound from your music phone with minimal disturbance often caused by mobile phone signal interference. Built-in folding stand to direct the sound - When enjoying your music out loud and on the go, you can easily prop up the speaker to direct the sound with the speaker's convenient, built-in folding stand. Universal: works via your device's 3.5mm headphone jack - Plug and play with any of your mobile devices that have a 3.5mm headphone jack  iPod, iPhone, GoGear, MP3 players, laptops, netbooks, music phones and more.