Premium quality black gum 1-hole rubber stoppers are a must-have for any science laboratory. These stoppers are designed to securely seal test tubes and flasks, preventing any spills or leaks during experiments. Each stopper is equipped with a raised figure on the top, making it easy to identify the size and ensuring a perfect fit for your lab equipment. Made from durable and resilient black gum rubber, these stoppers are long-lasting and resistant to wear and tear. Upgrade your lab setup with our reliable 1-hole rubber stoppers, perfect for all your scientific needs.