Yes it is. I am not sure what the max size is but mine is about 7 inches and thick. It's barbels are very long. I have a 125 and need a wider tank for it's barbels, it's almost 18 inches from the tip of one to the tip of the other.
Just checked he is more towards 8 inches. At the end of the video you can see I'm do a little barbel dance. This is a pretty old video put all my plants are hanging from the top to give him more space.
[video=youtube;eGZjhLvYRis]http://www.youtube.com/watch?v=eGZjhLvYRis[/video]
Awesome. I have him with a fire eel, 2 sengel bichirs, a cb endlicheri, 2 Raphael cats and a spotted. The Raphael are both 10 inches and I'm giving them to my friend today or tommorow thinking of a jack, or a green terror. Not sure.