Slips easily onto Buchner funnel stems and seals-off the filter flask mouth to prevent air leaks during vacuum filtration.
• Center hole fits funnel stems up to 22mm (?/10") diameter
• 9.5mm (³/8") thick by 76mm (2?/10") O.D. ring is wide enough to fit filter flasks up to 4000ml
• Made of chemical-resistant black neoprene