Compatible with many 3 in. flush valve American Standard toilets Please check your tank model for compatibility Durable rubber construction For use with American Standard tanks: 4000101, 4000101MX, 4000101R, 4000813, 4019001N, 4019101N, 4021001N, 4021101N, 4021128N, 4000107, 4000107R, 4000004, 4000104, 4117A101, 4117A101EZ, 4188A004, 4188A005, 4188A054, 4188A064, 4188A065, 4188A074, 4188A104, 4188A104MX, 4188A105, 4188A154, 4188A155, 4188A164, 4188A165, 4188A174, 4188B004, 4188B005, 4188B104, 4188B105, 4189D104, 4519A101R, 4519A104, 4519A105, 4519A151R, 4519B104, 4425A104, 4162A104, 4162A105, 4421A301R, 4229A101R 3 inch size