The PTRTP combines an active award-winning CompRT subwoofer a passive reFLEX sub and a power-matched built-in amplifier for an efficient pounding bass solution for your ride.FeaturesCompact factory-tuned enclosure for tight locations to fit many trucks and SUVsAmp is built-in and power-matched for hard-hitting bassEasily integrates with factory systemDown-firing for ultimate driver protectionThick tough internal bracing to resist stacking weightActive CompRT Sub matched with passive reFLEX? sub for extra outputRemote bass control includedSpace-SavingPlace them under a truck seat in the cargo area of your SUV or in your trunk �C perfect for many trucks or SUVs.Amp-Matched ImpactIt includes a built-in power-matched amp that integrates with most factory systems for hard-hitting bass.Rugged Enclosure Strength PTRTP Powered Down-Fire Enclosures are loaded with a passive reFLEX subwoofer and the KICKER CompRT active thin sub, delivering incredible bass Compact, factory-tuned enclosure for tight locations to fit many trucks and SUVs Amp is built-in and power-matched for hard-hitting bass Thick, tough internal bracing to resist stacking weight Easily adjustable with the included remote bass control