KAUFMAN, TX (11.10.2017) – Rocking the powerful features of packages 2 and 3, package 4 amps it up even further with the addition of a custom rack for the 1000 watt water resistant sub amp. An optional custom battery holder is also available for the suggested XS Power brand battery (Part #PS550A; CA: 550A; RC: KAUFMAN, TX (11.10.2017) – Rocking the powerful features of packages 2 and 3, package 4 amps it up even further with the addition of a custom rack for the 1000 watt water resistant sub amp. An optional custom battery holder is also available for the suggested XS Power brand battery (Part #PS550A; CA: 550A; RC: