One has the thumb inline with the back, the other one is shown and has the thumb release perpendicular to the back. Both wok, but you have to cut the inline one and superglue it to form and extension so the center of gravity of the phone doesn’t tip it over.
The one shown may not need anything done it. I have an HTC EVO with extended battery which is about the heaviest Smartphone out here and only a little shorter than the EVO 3D. If needed cut the tab to move the balance point forward and can also trim the top of the curve to increase lean angle.
I’ve designed one that is infinitely adjustable and fits in card slot of wallet. Will post after I go into production. It’s that good. Apologize but have had other designs copied for want of a more apt word and marketed without any credit (money) to me.
Couldn’t leave well enough alone. Cut off ribs, added ¼-20 bolt. Now it’s adjustable.