Easy-to-Use USB Wireless Transmitter for PC or Mac. This USB Transmitter is the perfect way to play music from your PC or MAC computer directly to your SMS Audio SYNC by 50 headphones. Using KLEER wireless technology for high fidelity sound, the USB transmitter connects your computer with the SMS Audio SYNC by 50 headphones without the need of a wireless network. When using the USB transmitter, FF and RW features will be available on ...