in to the factory location of a 4-inch speaker and can be driven by either a factory OEM radio or an aftermarket radio. It utilizes Plus One technology which gives you improved bass response. The Edge-driven textile-dome tweeter provides outstanding high frequencies and excellent reliability. This speaker can be driven with a 2 ohm impedance amplifier which gives you improved low frequency performance and louder sound. They can also be driven by a 4 ohm radio or amplifier. Infinity Systems is a leader in loudspeaker design for both car and home speaker systems and is part of Harman International. These speakers come with a one year parts and labor warranty.  (less)