This is an adjustable cradle to attach a smartphone to a standard tripod. The thread needed to fit to my tripod was a 1/4-20 UNC which seems to be about the standard, at least on the cheaper end of tripods, professional might be different. Fortunately I had the correct sized nut knocking about in the shed, one of those that 'might come in handy one day'. It should adjust to accommodate most smartphones. The photos show a Nokia Lumia 630 which is quite small, and a Samsung Note 4 in a protective case which is a bit on the large side but still some adjustment left. It also fits an Iphone 7, not sure about the 7 Plus. The V groove allows clearance for buttons/switches and assits in securing the phone. It might look a bit chunky and could certainly be refined a bit but once clamped in position you can be confident your phone is secure. Printed in ABS with a Flashforge Dreamer not Creator Pro. I used the standard ABS settings with a extruder temp of 220 and platform temp of 105. No raft, supports etc only pre extrusion. The main body parts were printed at 15% infill with the knurled knobs at 100%. The three main parts needed no post print finishing and fitted together beautifully. I inserted a 1/4-20 UNC nut into the base to attach to the tripod. The printed threads were a bit tight but a few runs with a standard M6 bolt loosened them up. As for the knurled knobs, different matter. These need a lot of refining in order to make them fit. Next time I'll just have 5 or 6mm thread and the rest just plain shank.