Check the listing for details. Alpine KTP-445A Head Unit Power Pack - Used, Open Box. Condition: Used. Listed at 296.96 USD. Hear the Difference with this Simple Power Upgrade!Add higher output and a more dynamic response with this easy-to-install Alpine head unit Power Pack upgrade. The KTP-445A Power Pack amplifies power output on select 2005 and newer Alpine head units, resulting in up to a 150 percent power increase over the original power from the head unit's built-in amplifier.Overview45 Watts x 4 @ 4Ω/2ΩFor select 2005 and newer Alpine head unitsCompact sizeEasy Installation and FlexibilityCompactCompact size lets the KTP-445A fit where most amplifiers won’t. The KTP-445A comes equipped with direct plug-in connectors for select 2005 and newer Alpine head units and it fits behind the dash of most vehicles. It's small and compact at only 7-7/16” x 1-1/2” x 2-1/2”.