- Flexible and durable conical silicone stoppers: made from high quality silicone, these stoppers are flexible yet sturdy. They have a dense structure that resists cracking and can withstand temperatures up to 200-300 C. - 60 pieces in 8 sizes and colors: set includes 60 stoppers in 8 different sizes and colors, compatible with containers that have threads or female threads and an inner diameter (ID) from 1/16 in to 5/8 in. The wide range helps you easily find the perfect size and color for your needs. - Safe sealing to preserve contents: features a smooth surface with excellent insulating and sealing properties. Provides reliable sealing to prevent leaks of liquids, powders and gases, helping isolate contents from air and maintain integrity. - Easy to use and reusable: conical design allows easy insertion and removal. Flexible and elastic for simple handling. Easy to clean and can be reused for a long time without staining. - Use scenarios: - Seal laboratory bottles, flasks, and storage containers to minimize evaporation and contamination - Seal kitchen jars and bottles to preserve freshness and prevent spills - Seal hobby or workshop containers to keep powders, beads, or small parts contained