Kartell 1759 90 x 165mm Manufactured from green ABS. the tubing selector gives nominal OD and ID of tubes/hoses. Additionally used to determine ‘grip’ for connector. The selector includes following gauges: ID’s mm 1 / 2 / 2.5 / 3 / 4 / 4.5 / 5 / 6 / 7 / 8 / 9.5 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17 / 18 / 19 / 20 / 21 / 22 / 25. OD’S mm 1.5 / 2 / 2.5 / 3 / 4 / 5.5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17 / 18 / 21.