For my OC-3 with Anderson blade plumbing that blocks the oil fill tube.
It's cut from a windshield washer fluid jug. I lucked in on the first try with one that had a handle long enough to reach the filler neck. Some jugs have shorter hand grips, as I found out when I misplaced the original and tried to make up another one....!
First attempt at posting pictures in a message - let's see if it works!
That's ingenious! We need to have an "Idea or Tech" section for work arounds like this.
Slick!