This is a smart-phone camera holder for a tripod. It is designed to fit a nut that fits on standard tripod screws.

Two kinds of nuts are supported, standard and one with an attached washer. The attached washer provides a bit more strength than a standard nut.

The tripod in the picture is "store bought" from Eddie Bower. It is many years old, but the screw is standard on camera tripods.

There is a hook provided on the top holder. It was intended for a rubber band to hold the top in place, but the rubber band is not necessary. Friction alone holds the phone snuggly in the holder.

This is designed for an iPhone 7 with a very slim case, but it will also hold a phone without a case.