Manufacturer Part Number: RS75-8 Incorporating a low-distortion motor system with a copper ring, a copper cap, and an aluminum phase plug, the RS75-8 can outperform "boutique" drivers that cost several times the price. Key Features: Full-range performance with low distortion and high resolution Durable construction with aluminum frame, aluminum cone, rubber surround Distortion-reducing copper ring, copper cap, and aluminum phase plug Subtle yet high-tech look makes a bold cosmetic statement Desi