Technivorm Moccamaster paper filters, size No. 4.
The Moccamaster KBGT 741 holds its coffee bed in a cone, not a flat basket, and the No. 4 is the wedge-shaped paper cut to line it. Fold the sealed seams over before you set the paper in, so it opens out fully and sits flush against the wall of the brew basket.
Size is what matters here. A paper that is too small leaves part of the cone unlined and lets water slip past the coffee, and one that is too large buckles and channels. Get the size right and the paper does its job quietly: it holds back fines and most of the coffee oils, which is what gives filter coffee its clarity in the cup.
