The Sharkk-O is a a portable, waterproof and dust proof speaker, that allows users to listen to music via bluetooth streaming, a built in Micro SD card slot or an AUX In port, wherever they are, at a range of up to 60 feet. Take this speaker to the beach, use it in the shower, bring it camping, the possibilities are endless. Additionally, 4W loudspeaker includes a built-in rechargeable 2200-mAh lithium ion battery, allowing for up to 8 hours of play time on a single charge. Overall this is a great option for anyone looking for a speaker they can take on an outdoor outing, receiving 4.5 out of 5 stars on Amazon. Users of this speaker claim it works well and is one of the best waterproof speakers on the market hands down. However, a fair amount of users wish the battery lasted longer, reporting only 6 hours of use while volume is on high.