This MB Quart Discus Series 8 in. 400-Watt Shallow Subwoofer is based on the company's popular RLP shallow subs. The steel baskets are stamp-cast and deep drawn. And it will work well in either sealed or ported applications. Shallow Mount – With less than 3 inches mounting depth, this car subwoofer is ideal in sealed enclosure applications and makes for one of the most versatile subwoofers for cars in areas with limited space. Deep Bass - Front and rear venting allows cooler air to be exchanged in the voice coil gap which helps the sub make deep bass and extend the life of the component. Built to Last - Heavy gauge powder coated stamped steel basket provides a solid base for the motor system and moving parts and delivers big bass in a small space that does not consume your cargo space. High Performance - 2 inch high temperature voice coil and former for high thermal stability in small enclosure volumes where the internal box temperatures can rob you of performance. Heavy Duty – UV rubber surround resists sun fading and remains flexible and the nickel plated push and insert resists corrosion and make for ease of installation.