For this price, the Deschem 1000ml Glass Suction Filter Kit Buchner Funnel & Erlenmeyer Flask comes highly recommended and is always a popular choice for lots of people.
Inner diameter of the Funnel around 70mm(Not Accurate)
1# Coarse Filter:Filtration Pore Diameter is 80-120 Micron
2# Coarse Filter:Filtration Pore Diameter is 40-80 Micron
3# Coarse Filter:Filtration Pore Diameter is 15-40 Micron
4# Coarse Filter:Filtration Pore Diameter is 5-15 Micron
5# Coarse Filter:Filtration Pore Diameter is 2-5 Micron
6# Coarse Filter:Filtration Pore Diameter is <2 Micron