It's almost identical. I picked up the sxk atto last month. Looking at promo shots of this soon after aside from the diameter and threaded sections I couldn't tell the difference. What I can't understand is, the sxk is a clone of the atto mod. The cthulu looks like a rebranded but wider sxk atto. Sometimes flak is given when companies clone high end devices. Now when an off the shelf company creates a similar device to a clone how is it not one and the same?