Product information Product Name: Black Silicone Rubber Hole Plug Material: Silicone Rubber Shore Hardness Range: 40-50 Temperature Resistance (from/to): -40��C to +250��C Function: Waterproof and Sealed Specification Size: 2.5mm x 30mm Colour: Black Shape: T Type Packing Quantity: 50 pcs Features: Corrosion Resistance, Acid and Alkali Resistance, High Temperature Resistance, Anti-ultraviolet, Anti-aging, Long Service Life, High and Low Temperature Resistance, Etc. Scope of Application: Suitable for various PVC pipes, steel pipes, equipment dustproofing, sewer pipe clogging, blocking different aluminum plate holes, etc. Can be used as spray plugs, test tube plugs. Warm Reminder: The Pictures Are for Reference Only, and the Size, Colour and Printing Are Subject to the Actual Product. Purchase Notes: The Size in the Specification Option Is the Size A in the Picture, That Is, the Size of the Part. The Small End of the Rubber Stopper Is Inserted into the Hole. When Choosing a Rubber Stopper, Try to Choose a Size Larger than the Actual Measurement Port to Achieve the Sealing Effect and Prevent It from Falling Off.