Here are the parts that you want from McMaster Carr as indicated in previous links:
5012K83 Acetal Quick-Disconnect Coupling Socket, 1/4 Cplg, for 3/8" Tube ID, with Valve
McMaster-Carr
5012K72 Acetal Quick-Disconnect Coupling Plug, 1/4 Cplg, for 3/8" Tube ID, W/O Valve
McMaster-Carr
If you need to replace the hose:
Hose:
51075K29 DURABLE NORPRENE RUBBER/PLASTIC TUBING, 1/4" ID, 1/2" OD, 1/8" WALL, BLACK
FORMULATION: A-60-G
McMaster-Carr
I have had in the past the actual coupling socket, 5012K83, fail and would not allow water/pee to travel through it. I didn't break it down to see why it failed, just replaced it.
You will want to order want to at least two (if not more) of the sockets and 4-5 of the plugs. The plugs are small and you will loose them. It does help to cut off about half of the tubing on the catheter as described above to avoid kinks in the system. Also after I have run my cleaning solution, 1/2 vinegar 1/2 alcohol, I put the plug back in and force air through it. You figure out how to get the air in there!!! Then just leave the plug in so it can dry inside.