This Emperor Aquatics Replacement Quartz Sleeve fits all Emperor Aquatics 65W UV Sterilizers manufactured after 1998. The outside diameter of this Quartz Sleeve is 1". Pre-1998 sterilizers have a different Quartz Sleeve, which we do not carry. It also fits the 130 Watt Smart UV Sterilizer Part# 02130 (which takes two 65 Watt Quartz Sleeves), and the 150 Watt Smart HO UV Sterilizer, Part# 025150. Pentair part number: FL-QZ167-IP. Length: 65".