Designed by a proven leader in studio reference monitors, Eris E4.5 BT speakers deliver studio-quality sound with the convenience of Bluetooth wireless technology. In addition to Bluetooth wireless connectivity, you get the flexibility of rear-panel, 1/4-inch TRS and RCA inputs; a front-panel 1/8-inch stereo line input for use with mobile audio devices; a handy front-panel volume control; and an integrated headphone amplifier.