I have the HT V2...but both the V2 and V3 use the Guardian new design. I got both sizes and i find it works very well. In essence the Guardian....decreases the diameter of the tube....and sort or wedges against the head of your clitty. There is a description of the Guardian and other devices at www.lockeduplove.net ...under the Holy Trainer section....and they have some pictures
I have both of the plain smooth new design....as opposed to the "ridge design" Here is the hyperlink to lockeduplove.net website and the page on the new Guardian design http://www.lockeduplove.net/product/htg2