There are many printable vacuum nozzles available, but nothing that fit the Karcher CVH 2 handheld vacuum. This adapter allows you to attach a 25mm (1 inch) nozzle. Note that the end of the nozzle that goes into the adapter should be around 23mm.

The small long nozzle shown in the pictures was from https://www.printables.com/model/316283-vacuum-nozzles-for-all-common-hose-sizes

Standard print settings are fine, no supports needed. I printed in PETG.