1,This winterizing plug is made of rubber and has maximum expandability to ensure a tight seal. 2,Used as a plug to plug the oil skimmer, return pipe and detergent pipe to prevent water from entering in winter. 3,Expansion plugs are also used for other purposes, such as pressure testing pool pipelines or other leak detection methods, or preventing water from flowing out of the pool during equipment maintenance. 4,Use this rubber expansion plug to protect your swimming pool from the harsh winter. 5,This pool winter plug strictly follows factory quality control, compact size and easy to carry. 1 x Winterizing Plug Item Type: Winterizing PlugSpecification: Approx. 63mm or 2.5inPurpose: Used as a pipe plug, plugging oil skimmer, return pipe and detergent pipeline-to prevent water from entering the pipeline in winter. Expansion plugs are also used for other purposes, such as pressure testing pool pipelines or other leak detection methods, or preventing water from flowing out of the pool during equipment maintenance.Weight: Approx. 145 g or 5.1 oz Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.