The overall outer diameter of a loop coil in centimeters, specifically the outside edge of the tubing ring. Marks the boundary where the wire path ends and the external field begins to fall off. The accessory's nominal size (e.g., a 15-inch loop) usually refers to this outer dimension.
A PEMF accessory takes a few physical forms, and the form sets how the field is laid out. A disc concentrates the field in a spot, a paddle puts that disc on a handle, a loop is a ring that surrounds a limb, and a mat spreads many coils across a wide surface. A loop is described by two diameters: the inner diameter of its open center and the outer diameter of the whole ring.
