J-hooks

A friend of mine has a Toyota 4-Runner with rials on the top that run front to back--no cross piece. He needs to car top his kayak but doesn't know which J-hooks to buy to fit those kind of rails (He says they're shaped like pyramids). Any suggestions?

They will need to install the cross rails that run side to side before putting on Jayhooks.

Vehicle fit-
Yakima
https://www.yakima.com/step1

Thule
https://www.thule.com/en-us/us/fit-my-car

J-hooks mounted on side bars ? That would be an interesting YouTube video going down the road with at least 2ft of kayak hanging off either side.... hope he ain't got a TI or other long ass boat