Guys we've been though this adapter thing a lot of times. Including earlier today.
There seems to be only one real source, it has two faces, the link above is the better of the two you get normal email confirmations of your order, notice of shipment and tracking number. From the other fellow at the desk on the other side of the room (?) you get none of those things. My shipment was addressed wrong (lack of email confirmation prevented finding this out until it got lost at the PO for an extra week before being sent back....where it sat until I emailed asking him to send it back. He said he would, then later said he had. After I asked for the tracking number, he finally posted it two days after he told me he had sent it. Can't recommend them at all. BTW, both sets of adapters were identical, came in the same plastic bag with both cards....
So, AFAIK there is only one choice. It doesn't look like either photo, but is like the OneLove adapter (which has the opposite threads) in that it seals to the cart and power supply. That is it's designed to force the cart to draw air up the hollow center of the adapter from below. This is standard for the 'self energizing' e-cigs out there, pulling on them works a switch inside the power supply that turns the heater on for you (no button to press). Since our power supplies don't do this and are in fact generally sealed to prevent leakage from wrecking them they won't draw. You typically can't get air out of your cart when everything is screwed down tight. Unless your 510 supply is vented (only one of mine is) you need to have the slots added so it can vent. And even when the supply is letting air though, filing the slots vastly improved the draw on mine. There is no reason for the seal in our application and IMO good reasons for not having it. BTW the TV adapter (again with the opposite threads to what we need here) has four such slots, I assume because they found the same issue.