Description Made of premium rubber with good elasticity, smooth and hardwearing. Used for filtration assemblies, together with a flask for filtration. Resistance to chemical action, resistance to acids and alkalies is excellent, except for hydrofluoric acid. Chemical, scientific research experiment, for decompression and filtration, use with filter bottles and filter paper. Features - Color: Green. - Material: Rubber. - Size: 8.40X8.40X3.20cm/3.30X3.30X1.26 inch. - Our filter adapter cones set come with 9 different diameters and flexible use for various sizes of experimental filtration apparatus. - Made of high-quality durable rubber with good elasticity, smooth surface, and wear-resisting. - It can be used as a single assembly or used for interlinking apparatus. - Reduce the damaged risks for glass stems when inserting or removing them through the rubber filter adapter cone. - Tapered collar design achieves good experimental result in seal. Good tolerance to acids and alkali.Package list: 9 x stoppers