KTP-445 - Alpine 4-Channel Head Unit Power Pack Amplifier
Easy to install, plugs right in to my Alpine unit (plug-n-play). Plenty of wires lenght included, makes for a flexible install, it is both good and bad. For a Jeep Cherokee, it fit perfectly behind radio, attached it with two metal screws, but the excess wire bunches up, so you have to make sure it does not get pinched as the wire harness gets sandwiched between the radio unit and amp.  After a couple of tries of sliding radio back in and adjusting the excess wires, it went in ok. It improved sound quality 