Sony's SRS-RF90R Wireless Speaker System is an optional speaker for the SRS-RF90RK. Perfect for travel, this portable speaker allows you to enjoy the sound of Sony audio wherever you go. Featuring 3 transmission channels, Automatic tuning, Receiver (Speaker) Compatibility with the Transmitter of the MDR-RF915RK and the MDR-RF945RK, a built-in 4-watt amplifier, and Reflector Technology - this sleek and stylish Wireless Speaker delivers superb sound.
