Polk - Wireless Multi Room Rechargeable Speaker - GrayThe Omni S2 Rechargeable offers a portable solution for taking Polks widely respected signature sound wirelessly to places without power, like on the patio or by the pool. The S2 Rechargeable is made of rugged ABS and has a lithium ion battery, enabling it to play up to 100 yards from your wireless router, even outdoors. The battery will drive the speaker for up to 10 hours on a full charge at moderate listening levels. The S2R is weather resistant