The Drumbass speakers from Lifetrons have product size: 4.3 cm x 4.3 cm x 4.4 cm and weight is only 54 grams . The size makes them as perfect travel accessories.  Music playing time is about 9 hours. Lifetrons promises “, stunningly powerful bass”, crystal clear sound and an excellent playback of the mid and high range tons. The price is about 100 dollars. You can check out their own website for more info.