Sony SA-RS3S Rear Channel Speakers for Home Theater, Wireless. 

Combine these optional wireless rear speakers with your soundbar to create an even more cinematic surround sound experience.
 

• Clear, expansive sound
  These two-way rear speakers feature both a woofer and a tweeter to achieve a rich, expansive soundstage with exceptional clarity.
• Total 100W output
  2 x 50W power output makes them the perfect support act for your soundbar, bringing movies and music to life.
• Omnidirectional block design
  An ideal match for your soundbar whether wall-mounted or freestanding with sophisticated rounded edges representing a single solid block of wide-spreading sound.
• Easy to set up
  Simply power up the SA-RS3S rear speakers and they'll automatically make a wireless connection with your soundbar. It's quick and easy with no need for messy cables.