Apple Watch Milanese band
Does the 45 mm for apple watch 7 is work with Apple Watch se44mm?
Apple Watch Sport
Question marked as
You can match most bands with any Apple Watch Series 3 or newer case of the same size. The 41mm bands work with 38mm and 40mm cases; the 45mm bands work with 42mm and 44mm cases.
The Solo Loop and Braided Solo Loop bands are only compatible with Apple Watch SE and Apple Watch Series 4 or newer. The 40mm and 41mm cases work with band sizes 1–9; the 44mm and 45mm cases works with band sizes 4–12.
from See compatibility details
when one choose a band in their store