What size is the O-ring on my power steering pressure hose??

It’s the other end, more like 5/16 probably even a 1/4” as the tube where is slide over is .265”. Was just hoping some had been through this before and had the magic sauce recommend. I will try a few
5/16 is .3125 and 1/4 is .250 so 1/4 would do it.