Is This An Ompok?

this is labled up as an ompok catfish, and the man told me that in an aquarium it would get to around 20cm.

i have since read that ompoks have 2 black spots, which this one doesnt.

any ideas?

i have found it here, can anyone verify the max size on here? also will it eat smaller fish?

catfish

Not sure it's Kryptopterus cryptopterus, but only because it doesn't seem to be a fish that is commonly available. Check out the Kryptopterus genre HERE. I'd suggest, if it is Kryptopterus cryptopterus, you should avoid mixing it with smaller fish, especially as it grows toward it's adult size of just under 8"SL.
I'd try and get some better pics, and be sure of it's ID before purchasing.
HTH
Martin