Beehive Frame Spacer

I bought a lot of used beehive frames without frame spacers.
This frame spacers are attachable with a screw (one is enough) to the frame.

There are two spacers:
The smaller one has the size of a normal Hoffmann spacer, the bigger one is a couple mm larger, I use it as a spacer for the drone frame, so that the bees can build the bigger.