That's a nice design for a divider! I like it. I followed this tutorial: http://www.tropicalfishkeeping.com/d...ividers-21866/
And added the blue strip things on all 4 sides to add strength. There are many types of dividers out there, homemade and storebought. I like this one because it's easily modifiable.
I LOVE the divider that was posted by Laki, it works wonders in my 10 gal. It also has tighter mesh so while the fish occasionally see each other, it's not too bad and not constant. :) Just my opinion there.
I have a homemade divider in my 5 gal (same as the tutorial Laki posted) and I put two sheets of mesh instead of one. My boys have never flared at each other - they can see movement on the other side but can't tell it's another male. It's worked great for me :)
Hm, never thought of using 2 sheets of mesh! For the future *rubs hands together*
I find the design in the tutorial is a bit flimsy, and if I didn't say so already, I used the binder things on all 2 sides to really make it strong.