Ruggedness and waterproof design: We give priority to speakers that are built to outlive the knocks and bumps of travel. We like speakers with an Ingress Defense (IP) ranking, which informs you exactly how dustproof and waterproof a speaker is. All airlines have size and weight restrictions for products https://www.bluetoothspeaker.top/sound-system-speaker-surround-soundbar-computer-speaker-for-tv-soundbar-box-subwoofer-stereo/