These are very easy to use unlike most adaptors I have found for mounting phones to microscopes to take pictures or videos. While each adaptor is specific to a given phone design and microscope eyepiece, they are fairly easy to make. In the 1 MB pdf file, I give instructions for the novice to design these in Fusion360 and subsequently make and use them. Yes, the stl file here will likely not work for you, but it is provided so you can get a sense of the item.