Achieving an IP67 rating, the item has serious dust and water protection built in. In fact, not only can the it withstand a splash or getting caught in the rain, but it can also survive being submerged in up to 3' of water for up to 30 minutes.a rubber fastening strap on the back of the Willen Ii gives you flexibility in how you enjoy your audio. Hang it from a backpack strap or handlebars while you're on the go, or a fence when at the park or pool with friends. It's a great way to keep your hands free and the Willen Ii nearby to enjoy.Even in such a small frame, Marshall manages to supply their signature balanced sound with punchy bass from a single 2"" 10W full range driver, dual passive radiators, and a 38W Class-d amplifier.