Based on this product's specifications, here are some alternatives and similar models
Filter Head Clips for UVC-Xtreme 800/1200 by sera — set of 2
Summary description:
Replacement clips for the filter head of sera UVC-Xtreme 800 and 1200 models. This set contains two original mounting clips designed to secure the filter head to the housing, ensuring stable attachment and correct alignment of UVC components. Suitable for maintenance and repair of compatible sera external aquarium sterilizers.