Product: Sony Active Subwoofer (Built-in Amplifier). Driver Size: Powerful 8.5-inch driver. Condition: Perfect working condition (Fully tested, no issues in performance). Sound Quality Delivers deep, rich bass and clear overall sound. Usage: Suitable for home theater setups, general music systems or car audio enthusiasts (Please check compatibility for car use). Ease of Use: Simply plug and playready to enhance your audio instantly! Note for Buyers: Only genuine buyers please contact.