Scanner slides over your phone, choose one that fits your phone model.
Click Settings, General, then About to double check what iPhone model you have.
MAX and PRO are different size phones, make sure to get the right scanner for you.
If you change you phone later on, you can always get a new case for $9.99.
Shorts are very stretchy and come in two overlapping sizes.
Small/Regular stretch from size 00(24) to 16(33) and Regular/Large stretch from size 8(29) to 22(36). If you are size 10 and up go for Regular/Large.
Don’t worry if you are not sure, there is a big overlap between sizes.
And if both sizes fit you, go for the larger one, it will be easier to measure.