What kind?

anyone know what kind this is? Or how big it gets? pet store guy claimed "it wont get much bigger in captivity"... if it wasnt so cute that blatant lie woulda made me leave immediatly... i know darn well the thing isnt gunna stay 2 inches, and rather expect to end up with something 3+ feet. he claimed it was an "ornamental softshell". My cam is low quality, but its a tanish colour, with some pin-prick sized black spoits, and around the edge of the shell, the black spots are thin broken lines.
on his front legs theres a few "scale" looking bits of skin, im assuming they ARE soft scales, but ive never really kept turtles before, always been a lizard girl.