At least that is what they are called in the JC Whitney catalog.
I have put them on several cars. Believe it or not, they attach with double sided tape.
They are specifically made for particular car models. You can't just order one for a Boler
door. You'd have to have your dimensions in mind and when you see a car with the approximate correct ones, remember the model of car to order them.
To the best of my knowledge they don't sell them as say...for 28" windows
, they sell them by car model.
They are nice though, and it is a really good idea.