Wireless Compatible so you can get the optional wireless headphones like the EQX 800 has, or any wireless bluetooth headphone you want to sync up to it! Long Life Rechargeable Battery lasts 12 Hours. Multiple Frequency, or you can run it on single frequency modes, 5 kHz, 10 kHz or 15 kHz, or Multiple Frequencies! The 600 operates the same as the 800 in Multiple Frequency Mode! Waterproof to Ten Feet and two level Backlight, Built in Loud Speaker, Magnetic Charging Connector, and more!