The UE Wonderboom 2 plus the UE Boom 3 are quite portable and durable. The Wonderboom is slightly more portable than the other two, weighing in at 15 ounces and boasting IPX7 waterproofness. Its shorter and stout shape also will help it disappear inside of the backpack. This speaker https://www.bluetoothspeaker.top/hot-selling-high-quality-round-bottle-active-subwoofer-rechargeable-wireless-speakers/