Double hook for 40x20mm metallic bar

I need some fairly solid hooks to hang various objects above my head in the garage. These hooks should be attached without drilling to a grid fixed on the ceiling of the garage made of 40x20 metal bars (anyhow, I left a screw hole in the model in case a better fixation is desired). Also, I can move them whenever it is needed to another part of the support bar.

The model is a remix of Hugo Pereira Wall Hook to which I have made some changes (the grip mode and one of the lip of the hooks is longer).