this 36 watt UV light bulb is a standard four pin base that fits Tetra, Sunterra 36W UV Clarifier, Terminator, Jebo, Coralife Turbo Twist, Cal Pumps (older Units), CaluTech Original "Blue" Air Purifier, Aqua Medic Helix Max 36, Fish Mate Pressurized 9000, Odyssea 36W Clarifier, Oase Bitron 36 Clarifier, Bitron 72 Clarifier, OASE Bitron 72C UV Clarifier, Bitron 36C UV Clarifiers, SUNSUN CUV-136, Jebao PU-36, Haqos 36W UV Sterilizer, ViaAqua 36W UV Sterilizer, York S1-UV50120 Hybrid UVC Air Purifier, and more.