The Sunpark SL15T is an electronic two light fluorescent ballast. It is designed to operate (1 or 2) F25T8, (1 or 2) F32T8, (1 or 2) F20T12, (1 or 2) F25T12, (1 or 2) F30T12, (1 or 2) F34T12, (1 or 2) F40T12 linear fluoresents or (1 or 2) F26DBX G24q-3, (1 or 2) F26TBX GX24q-3, (1 or 2) PL-T32W, (1 or 2) F36BX 2G12, (1 or 2) F39BX 2G11, (1 or 2) F40BX 2G11 4-pin. The Sunpark SL15T has had a wiring change by the manufacturer. If you need assistance from us on the simple conversion email us . This is not the versions with sockets attached for circline lamps. That would be the SL15T-1 .