The Emperor Aquatics Smart UV Sterilizer Service Kit includes all the gaskets and o-rings for the Emperor Aquatics Smart 25w UV Sterilizer, Emperor Aquatics Smart 40w UV Sterilizer and Emperor Aquatics Smart 65w UV Sterilizer. This Kit WILL NOT work for the Smart Lite UV Sterilizer. Those Sterilizers have a 2" body. This Service Kit is also NOT meant for the high output Emperor UV Sterilizers. NOTE: they recently changed the Quartz Sleeve Gasket. It no longer needs to have the small o-ring next to it.