Standard gardena / garden hose to ¾ pipe thread adapter, as it is used in e.g. sprinkler systems, pumps or water switches. This version has a sharper design with edges and knurl. Seal and O-Ring can also be found in my other models. Print in high quality for a good thread, will still need a bit of force on the first screw action. Happy watering :)

Disclaimer: I use the term Gardena as a reference term for the famous garden hose connecting system. I did not take any replicas from their designs or IPs specifically. I did my measurements and testfits on *any* system adapter I had laying around without the knowledge who made it.