Fits Jupiter Models - Delphi, Athena, Melody, Venus, Neptune, Microlite, Aquarius, Orion, Mavello & * Also FOR Regency Elite Regency X Alakalife 3000SL * NOT FOR - Technos, Ultra-Technos, HTH, Masterpiece, Midas, Regency II, AlkaBlue or Aqua Tonic * The top opening is 1/2" inside diameter ; The bottom opening 3/4" inside diameter * Filter is 8 3/4" Tall; 3" Diameter - Made in USA with NSF certified components.