The Kenford L200006-4B high-temp copper wire voice coil is wound on a durable polyimide former, guaranteeing maximum heat resistance and excellent mechanical strength. The Kenford L200006-4B features a specially designed force air ventilation system to ensure proper cooling of the voice coil for long hard play. The Kenford L200006-4B PA Woofer is a powerful upgrade for guitar, bass guitar or sound reinforcement cabinets.