BP question, and O-Pac follow up

[sumguy]

This is probably a stupid question, but how does a wing mount to a backplate, if no STA is being used? Bolts? And on the O-Pac, which looks flat in the pictures I've seen, wouldn't the bolts dig into your spine? Assuming you dove without the padding.
Or is it just the tank straps that hold the wing on?

 

[Scubaroo]

The O-Pac uses the cam straps to hold the wing between the soft pack and the tank. You can also use some zipties in the grommets of the O-Pac and the wing to keep it more "together" when no tank is mounted if desired.