Frey Scientific Natural Cork of size 0 features 10 mm top dia and 8 mm bottom dia This product contains small parts making it a choking hazard Only use with adult supervision Our products are not toys Use in a laboratory or educational setting only Not for children 13 and under Features. Frey Scientific No0 Coarse Grained XX Grade Natural Cork. XXgrade coarsegrained stopper may include some irregularities. Cork is ideal for corrosion resistance. Keep your science stations stocked with these laboratory essentials. Pack of 100Specifications. Size 10 mm Top x 8 mm Bottom Dia. Country of Origin Portugal. Safety Choking Hazard Small Parts Not for children under 3 yrs. Allergens Contains No Allergens. Bottom Diameter 711 mm. Material Cork. Material Type Cork. Size Size 0. Top Diameter 914 mm