4 points correspond to the nominal diameter DN15, i.e., a diameter of 1.5 cm;
6 points correspond to the nominal diameter DN20, i.e., a diameter of 2 cm;
1 inch corresponds to the nominal diameter DN25, i.e., a diameter of 2.5 cm;
1.2 inches correspond to the nominal diameter DN32, i.e., a diameter of 3.2 cm;
1.5 inches correspond to the nominal diameter DN40, i.e., a diameter of 4 cm;
2 inches correspond to the nominal diameter DN50, i.e., a diameter of 5 cm;
2.5 inches correspond to the nominal diameter DN65, i.e., a diameter of 6.5 cm;
3 inches correspond to the nominal diameter DN80, i.e., a diameter of 8 cm;
4 inches correspond to the nominal diameter DN100, i.e., a diameter of 10 cm;
5 inches correspond to the nominal diameter DN125, i.e., a diameter of 12.5 cm;
6 inches correspond to the nominal diameter DN150, i.e., a diameter of 15 cm;
8 inches correspond to the nominal diameter DN200, i.e., a diameter of 20 cm;
10 inches correspond to the nominal diameter DN250, i.e., a diameter of 25 cm.