The SR2 is a pair of wireless surround speakers for selected Polk sound bars. Each cabinet has its own amplifier and needs only mains power, not a speaker cable back to the bar.
A rear-channel add-on for Polk React and MagniFi systems. The two cabinets are labelled left and right and can be wall-mounted or placed on a shelf. They pair wirelessly with the sound bar and are sold as a pair.