Will the Modern Strap Slim fit my Apple Watch 38mm Series 1, 2, or 3?
The Modern Strap Slim is designed for Apple Watch 40mm Series 4 & 5. However, this strap will also fit Apple Watch 38mm Series 1, 2, or 3 with a slight lug misalignment.
The lugs that connect the Modern Strap Slim to the Apple Watch are a bit wider than the lug inserts on the Apple Watch 38mm Series 1, 2, and 3 so the lugs will extend slightly beyond the edge of the Apple Watch case on these models. This misalignment will not hinder your ability to use the Modern Strap Slim, but you will see a minor cosmetic flaw with the fit of the strap in your Apple Watch as seen in the picture below.