The S2 Rechargeable offers a portable solution for taking Polk"s widely respected signature sound wirelessly to places without power, like on the patio or by the pool. The S2R 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 up to 10 hours on a full charge at moderate listening levels. The S2R is weather resistant and ruggedized for casual outdoor use. Infrequent and or accidental rain and sun exposure should not harm the S2R.