Behringer Studio 50USB 150W Bi-Amped Reference Studio Monitor Speakers with USB Input, High-Resolution, Pair Behringer Studio 50USB 150W Bi-Amped Reference Studio Monitor Speakers - Behringer 3 Year Warranty Power: 150W Input: USB Woofer Size: 5" / 12.70cm Silk Dome Tweeter Size: 1" / 2.54cm