The Dark Inception is a little firmer than the Inception. That firmness helps it go in easier. and makes for more stimulation for the top. The flexible TPE protects the wearer's ass. allowing him to bottom for way longer while also feeling more filled up. Meanwhile the top gets a tighter sensation. and gets to dump his load in the Dark Inception.
You can use water or silicone based lube with the this big fuckable butt plug. Just wash it off with soap and water when you're done.