The Aqua-Pure APUV2 Ballast R is the correct replacement ballast for the following UV systems:
The Aqua-Pure Replacement APUV2 UV Ballast is an electronic ballast that fits the Aqua-Pure APUV1, APUV2, APUV6, and APUV8 UV filter systems. This replacement UV ballast provides consistent ultraviolet output over a broad range of voltages and frequencies. The APUV2 ballast easily handles variations in power so that you won't have to switch off your unit.
Aqua-Pure 5605859 Replacement UV Ballast specifications: