Ultimaker Side Closure Mount

As I mounted my new fan duct made of aluminum sheet metal onto my Ultimaker, I found the chance of closing the sides of it with simply adding two sheets of acrylic.

BUT: How to mount...?? Screw?? No... Glue? No... Magnets? YEEEAAAA

So I designed this simple brackets to glue in the edges of the plywood frame. Each of it holds a small D=3mm s=mm neodym magnet in place while a counter magnet is glued onto the acrylic window.