Crimp hose fitting ending in a plain standpipe with the outside diameter of a metric tube. The standpipe goes into a DIN 2353 (ISO 8434-1) 24° cone union and is tightened with nut and cutting ring, just like a rigid tube.
Tube: from 6 to 42 mm outside diameter
Hose: from 3/16" to 1.1/2" inside diameter
Straight, standard series
In each option, the first value is the tube diameter and the second the hose inside diameter. Choose the tube size of the union it will connect to (see the marking, for example 12L or 16S). The nut and cutting ring belong to the union.