With MB Quart, we strive to push the boundary in perfecting sound. The all-new, top of the line, Premium Series truly makes Music. Defined. The Premium Series will offer you levels of clarity, coupled with rich quality sound, creating superior audio for all of your playlists that simply demand the best. High temperature adhesives are utilized to keep the coupling from cone to surround fused and are also impervious to cold weather. Molded Polymer Sealing gaskets are utilized to keep the speaker isolated from the mounting surface and improve protection from the water and dust intrusion. Stainless steel, push and insert connectors resist corrosion and create a superior electrical connection. Red woven fiber cotton poly blend spider to stabilize the cone and voice coil in all musical situations. Venting allows air passage through the spider and speaker frame ribs to exchange air over the voice coil.