Pagow Buchner Funnel Flask Adapter Set, Filter Adapter Cones Set, Tapered Collar Specification: Material: Neoprene Size: Set of 9 neoprene adapter cones designed to fit Buchner and fritted glass funnels Set of 9 different size neoprene adapter cones designed to fit Buchner and fritted glass funnels Made of Neoprene: These adapter cones are designed to fit around the stem of Buchner funnels, porcelain filters (minus headpieces), and fritted glass funnels. Extremely useful in the reverse flow cleaning of filter crucibles. Widely Used:Perfect for supporting funnels, Gooch crucibles, filter tubes and other apparatus that are routinely used in filtration assemblies. With different sizes of adaptersL: can be used individually or in a nested combination with ones or more adjacent sizes. Fully autoclavable:Fully functional even if they are not tightly fitted around the stem of the funnel being used. They are also an excellent alternative to boring special sized holes in rubber stoppers, or using the more unstable rubber filter aid.