POLAM-FOTOUniversal Cell Phone Tripod Adapter Adjustable Phone Holder Mount 2 Pack, Tripod Mount, Fits iPhone Samsung and All Phones, Rotates Vertical and Horizontal, Compatible with all tripods

Compared to others I have tried, these holders do not have attachments for cold shoes on cameras, and do not fold on themselves, reducing the space they take when stored attached to the tripod.However, I prefer them because they have a nut locking rotation, so they do not wobble at all once locked, which is something which was bothering me when taking videos and photos with the others I have.Also, that means that they can be locked at any angle precisely, rather than having to deal with rotation in steps.It is all pretty thick and sturdy plastic, and, while there is no cold shoe attachment, there are tripod mounts on a few sides, so one could mount an adapter for cold shoe.The jaws are sufficiently padded and tall enough to clamp other square sided objects, such as portable recorders.Lastly, the jaws open and close via a screw, which is less quick than the usual spring clamps, but also easier to do without putting any pressure on the tripod and ball head, which can be handy.For the price, at £12 for two, I think they are pretty good.