These tend to look a bit like a stapler, but they trim your card down to the correct size and shape. If on the other hand your SIM card is too small for your phone, then you can get a SIM adapter.
While drywall ceilings are most people's go-to, they're not a good fit if you want to keep your basement ceiling accessible.
The screen protectors give us a fair idea of the display size difference between the three models. The Galaxy S25 Ultra screen protector also highlights the updated display design with rounded edges.