So what's a good number range to look for? We recommend just about anything among a four and 6, but seven and higher might be a premium rating and able to withstanding whole water submersion. The Sonos Roam is the one speaker we tested that's setup to take advantage https://www.bluetoothspeaker.top/bluetooth-wireless-speaker-audio-stereo-tf-card-mobile-phone-support-universal-battery-powered/