Comes in 10-Pack, size: 1#; StonyLab premium silicone stoppers provide exceptional seal for lab bottles, vials and other containers, Exhibit excellent resilience and retain pliability over a long period; resistant to chemical reagent and heat; can withstand high temperature up to 250 degrees Celsius, With good sealing performance and can effectively prevent solution leakage; please note these rubber stoppers are not food grade, Durable and reusable; please read the dimension description image carefully before making a decision (might have 1mm measurement error), Warranty: StonyLab 1-year limited warranty; if received damaged, please contact us immediately; we will solve it until satisfied