Will my 42mm Apple Watch bands for the series 3 fit the 40mm Apple Watch series 4

You can match this band with any Apple Watch Series 4 case of the same size. It also works with all previous versions of Apple Watch, including Apple Watch Series 3. The 40mm band works with the 38mm case; the 44mm band works with the 42mm case.

I have a friend and she has a small wrist.

She uses a 38mm watch band on her 42mm watch - as I understand it ALL watch bands will fit ALL watches - the 38mm and the 40mm slot (area of watch that band slides into) are the same as are the 42mm and 44mm - If I remember it is like 1.4mm difference?

Happy watches! 🙂

YES!...

ALL MY SERIES 3 42MM BANDS FIT.

PARDON CAPS NEED FOR VISION SINCE STROKES.

PEACE AND GODS BLESSINGS WISHED FOR EVERYONE...