For this amazing price, the 7cm Dia. (2.75") Filter Funnel, Buchner Style - 2 Parts, Polypropylene, Designed for 5-6cm Filter Paper is highly recommended and is a popular choice amongst most people.
Polypropylene in two piece - it is both lightweight and autoclavable. The top portion can be fitted with the lower one, forming a vacuum seal which does not require greasing. The base of the top portion has a perforated filter plate.