These white cone filters are made for brewing single-servings of drip coffee. They are to be used with our single-serve drip funnels.
For best results, fold over the bottom crimped edge and the side crimped edge prior to insertion into the drip brewing funnel. This will give you a secure fit.
Note that the #4 cone filter has an edge that's 4.5" long, and the bottom edge will be 2" across after it's folded. See the attached drip funnels that these filters are for use with.