There are punch outs in the center and in each corner. It takes getting used to place in the filter compartment, but it isn't too difficult. The 4 pack is the best price per unit, although amazon notes that the one pack is.

Electric percolators perk very fast the last quarter or so a the brew cycle. These filters are perfect for my 12-cup percolator.

The paper filters out the oil, then lifts out all the grounds without spilling any. These filters help smooth the flavor and makes clean up of the grounds super easy.

Product defective. Must return item to replace; no refund w/o return. Shame on melitta for misrepresenting this product. They are not returnable!