Sorry I missed your question! Feel free to throw rocks my way to get my attention if needed!
I will measure it when I get home tonight.
Hummm.... I've never needed it any larger since my two largest fish enter, turn and exit with ease.
I have removed the 'arms' that came on it. They allowed it to hang on the edge of the aquarium. I tried using it like that but the fish were too shy of it. They are not as comfortable with the trap hanging over them as they are with it sitting on the very bottom; so I removed the 'arms' and use it strickly on the sand now.