What is this?The Rubber Tapered Plug is great for laboratory utensils such as flasks test tubes or other laboratory applications also can as a sewer plug water pipe plug or drain plug.What will I get?The tapered plug is in size of: Bottom Diameter: 33mm / 1.3 inch; Top Diameter: 41mm / 1.61 inch; Height: 25mm / 0.98 inch; In the package of: 5 x Rubber Tapered PlugAre there any advantages of the product?Made of Rubber with good resistance to chemicals acid and alkali resistance can withstand high temperatures in a short time.How to use it?Conical design solid easy to install and good sealing performance flexible and durable not easy to crack shrink harden or break. What should I notice?Please check the size carefully before ordering! This product has a smell please put it in a ventilated place before use to reduce this smell.