Finum permanent tea filters feature a very fine stainless steel mesh with a permanent goldtone finish produced by processing the stainless steel at very high temperatures. This finish helps minimize interaction with the tea. These are perfect for small or large mugs and teapots with a round opening. Medium: overall height, 3.25"; rim diameter minus handles, 2.5". Large: overall height, 4"; rim diameter minus handles, 2.75".