I think 2 different watch sizes are absolutely necessary. There is no way that one watch size will fit across the varied wrists of both men and women. Both may

I think 2 different watch sizes are absolutely necessary. There is no way that one watch size will fit across the varied wrists of both men and women. Both may feel fine for a average sized wrist, but start moving up or down from that wrist and one size quickly becomes a problem. Look at the Moto360. It's so large that it only looks decent on the largest of wrists.