Sta-Kon F4027 INS PP OLD DIN FERRULE No16 1.5MM2

The F4027 wire ferrule is sized for 16 AWG conductor, which is the 1.5 mm2 metric equivalent called out in its description. If you are terminating 14 AWG or 18 AWG, you need a different ferrule size, since a ferrule has to match the conductor cross section to crimp correctly.

Black is the insulation color on the F4027. Ferrule insulation is color coded by wire size, so on a panel the black sleeve is how an electrician tells a 1.5 mm2 / 16 AWG ferrule apart from the other sizes in the drawer without measuring. Note this one follows the old DIN color scheme rather than the newer standard, so don't assume black equals the same size across every brand on your bench.

Copper barrel with a polypropylene insulating sleeve. Copper keeps the termination conductive and crimps down tight on stranded conductor; the polypropylene sleeve is what strain-relieves the strands where they enter the barrel.

A ferrule is what you use when stranded conductor lands in a screw or spring-cage terminal. Crimping the copper barrel of the F4027 onto the 16 AWG strands turns them into a single solid pin, so no strand escapes under the clamp and the screw can't shear individual strands. If you're landing solid conductor, you don't need one.

Germany. Country of origin is listed as Germany (DE), which is the documentation a procurement buyer needs for origin reporting on a bill of material.