The GRS 5PF-8 5-1/4" woofers feature a poly-laminate coated cone and a foam surround. They are ideally suited for all sealed-box speaker applications. Thanks to their carefully optimized parameters, GRS 5PF-8 5-1/4" poly-laminated paper cone woofers offer a high degree of compatibility when used as replacement speakers—they also provide excellent performance in new projects, too.