●CONE Made of polyurethane, the CH3220 3.5 inch car speakers offer a resilient and durable material that can provide great sound with the benefit of durable speakers ●Tuning coil: our voice coils are able to withstand high temperatures but retain their strength and fatigue properties, giving them the advantage of longer playing times with lighter weight ●SURROUND: We use rubber in many of our speakers. It has the ability to endure a lot of punishment without signs of damage. It complements the entire structure of the speaker by allowing constant abuse where it is needed most, without wear and tear ●Tweeter: a piezoelectric tweeter is more resistant to overloads and can be used without crossover due to its electrical properties. ●Warranty: BOSS Audio Systems offers a powerful 3 year platinum online merchant warranty as long as the purchase is made through Amazon Dot Com