This model is sized for a Samsung Galaxy S23+ with a slim case (Urban Armor Gear Civilian Series), but it may fit others as well. See images for size (measurements are in inches).
It fits in the Life Fitness Treadmills with the iPod holder. There is a recess on the mount for the cable on the treadmill to slide into.
If you want it sized for your phone, reach out and I can modify the design and upload your version.
The author marked this model as their own original creation.