Karcher WD2 WD3 WD4 connector 50mm 2" 40mm pipe

Here I made two types of connectors, which work with Karcher vacuum cleaners - WD2, WD3, WD4 familly etc :

1. for 40mm spiral pipe 
   - with “left” thread
   - with “right” (normal) tread
2. for 50mm pipe:
   - straight simple version (for non-spiral pipes)
   - with “right” (normal) tread for spiral pipe
   - with “left” thread for spiral pipe

Connector is made from 2 parts - connector base (version to chose from above), and standard “lock” (which should be printed on side). Lock should be glued (i use T7000 glue for PETg), but it holds without glue too (snap-in in place)

EDIT: Version 2 reviewed. 

Changes: 
- additional groove for O-ring on vacuum cleaner side. 

A 50mm O-ring seal helps improve the seal and eliminate air leaks. It also reduces play in the seat. It's not necessary, but it helps.

- improved aerodynamics, reduced airflow noise.

- in threaded versions - improved thread thickness so that the flexible tube is screwed on more tightly and holds the wire to the thread better.