Originally Posted by
tropit
What's a "hump jumper"??
This site shows the one that I have.
https://napasewandvac.com/the-hump-jumper/
It's a piece of plastic that you put either behind or in front of your foot to keep the foot even and thus sewing. I've used them in many projects for years. They work great and are very inexpensive. I have the same set I bought in probably the late 80's. They're still fine and have been used a lot.
Tranum, a Jean A Ma Jig is sort of the same thing.