Measurement following the exterior curvature, from the lowest point on the front of the case to the end of the horn, without adapting the measuring tape to the roughness.
2. Perimeter of the horns at the base
The perimeter at the base is measured perpendicular to the axis of the horn, without taking into account its edge.
3-4-5. Perimeter of the horns in each quarter
The length of the longest horn is divided by four and the measurements of each quarter on both horns are marked, measuring the section at each marked point.