Compatible models: SV-404, SV-S500, SV-55V6, SV-405, SV-S501, SV-KS500, SV-504, SV-S502, SV-KS501, SV-505, SV-S503, SV-KS502, SV-507, SV-507, S7, SV-KS703, SV-KS703, SV-KSV-KS703, SV-KS703, SV-KS503, SV-KSV-KS703. V-508, S V-S701, SV-KS504, SV-737, SV-S702, SV-KS505, SV-738, SV-S703, SV-Z507, SV-K510, SV-T502, SV-Z508, SV-K520, SV-T503, SV-K505005 SV-Z50. 1, SV-K540, SV-K506, SV-Y501, SV-M504. This is a replacement cleaning filter for humidifiers.