size of Apple 5 watch for alternative band

Do you have the 40mm or 44mm Series 4 watch or the 38mm or 42mm series 3 watch? the 38mm replacement bands fit the 40mm watches and the 42mm bands fit the 44mm watches.

There is no Apple Watch 5. If you want a band for the Apple Watch 4, just Google Apple Watch Bands.

This might be helpful....https://www.apple.com/shop/watch/bands?afid=p238%7Cs4Wh17l9E-dc_mtid_1870765e38482_pcrid_339134119347_&cid=aos-us-kwgo-btb--slid--apple+watch+bands-e-product-