The JBL 363686-001 5-1/4" treated paper cone woofer is a direct drop-in replacement for the popular JBL Control 1 Pro and Pro III mini monitor speaker systems. With the exact same construction and specs of the original drivers, the 363686-001 restore your classic speakers to like new condition. The treated paper cone and damped foam surround keeps resonances to a minimum. A fully shielded magnet assembly allows close placement to any devices that might be sensitive to stray magnetic fields.