Alpine R2-W12D2 Car Subwoofers The set screws are tightened/loosened

The set screws are tightened/loosened with the included 2mm Allen wrench

Mica Reinforced IMPP™ woofer cone

but it's even better when you add great sound

61 in / 66 mm Surface Mount Fixture Diameter (A2) 2

Alpine R2-W12D2 Car Subwoofers The set screws are tightened/loosenedAbout the Alpine R2 W12D2 Maximum bass output With over 40 years of experience, Alpine has the know how to deliver the kind of hard hitting bass you want. The R2 W12D2 12" sub capitalizes on this knowledge with a new motor structure with double stacked magnets for deeper bass and tighter sound. Its Kevlar reinforced pulp cone features a durable HAMR Santoprene surround that allows for huge amounts of excursion, and an oversized poly ceramic dust cap