Material: Made of silicone, these hole plugs are not only waterproof and dustproof but also exhibit good heat resistance, low temperature resistance, and durability. Good Seal: With its high resilience and snap-in design, the Silicone tube plug ensures a good seal for a wide range of applications. Multiple Use: Good for using as sealing hole plugs, waterproof plugs, test tube plugs, threaded rubber plugs, dust proof plugs hole covers, etc.