Milanese loop magnetic closure band

All Applw Watch bands are intervhangeable provided you buy the correct case size fit. There are only two sizes.

Bands which are 38/40/41mm will fit any Apple Watch which is 38/40/41mm 

Bands which are 42/44/45mm will fit any Apple Watch which is 42/44/45/49mm 

There is a compatibility link on most pages for Apple Watch bands,

Band Compatibility

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, 44mm and 49mm 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 1–12.

Basically, if your Apple Watch is compatible with Solo Loop it will be compatible with Milanese bands. If you have an older model and want to change to Solo Loop, please see the quote above.