Review on Adjustable Holding Capacity GH 4002 Lockable by John Hall

You have no chance of having a working system unless the two surfaces are perfectly flat. If the hook is even slightly above the loop, it will not enter it because of the corner. The hinge really needs to be square and not triangular to allow for some angular play. If you shorten the screw, it also sticks out at the back, preventing it from tipping up.