Summary

Led Sign Extrusion Coupler used to connect two pieces of the extrusion together.
This makes it possibe to take two LED signs and make a much bigger sign.
For instance you can take two $400 160 by 64 LED signs and make a 160 by 128 Sign.
You might need a new LED sign controller like a D16 controller as well.
I recommend you stretch it to 40 or 50 mm and lay it down to print it as in the picture.
That will make it longer and stronger, use lots of glue when assembling your frame.