Pebble wants to make super sure that you buy the right size of the Index 01 ring, so they send you a 3D-printed (or you could print your own) set of mockups at all the sizes. They ask that you test them and keep the best size on your finger for a day to be confident you’re happy with it. Good idea!

A hand with a dark rectangular clasp ring on the index finger. In the background, there are several similar rings laid out on a colorful, rainbow-themed mouse pad with an animated figure in a red outfit. A USB cable and part of a monitor stand are also visible.