The ST100500 is used to remove the Sloan Flushmate Cartridge. It is used on all Sloan Flushmate Systems. Fits tanks 500, 501, 501A, 501B, 503, 504, F31A, F3A, F3AR, F3C, F3CR, F3CC, FCE, F3ER, F31, F3G, F3G2, F3L, F3LR, F3, F3R, F3M, F3MP, F3MR, F3O, F3U, F3UR, F3Z, F32, F3K, F3KR, F3G4, F3G3, F3GR, F3K1, F3K2, F4A, F4AP, F4P, F4L, F4LR, F4N, F4B, F4C, F4K, F4KR, F4MP, F4J, F4M, F4V1, F4V2, F4V. Fits all American Standard, Briggs, Caroma, Ceralux, Eljer, Gerber, HCG Hocheng Corp, Kohler, Lamosa, Mancesa, Mansfield, Niagara, Orion, Peerless, St. Thomas, Vitra, Vitromex, Vortens, Western Pottery, Xinqi