As ever, you still need to stay in the same smaller or bigger watch version to keep band compatibility.

What are the new Apple Watch sizes?

Apple Watch Series 7 comes in two new sizes: 41mm (smaller size) and 45mm (larger size). Here’s how band compatibility works with the new sizes:

• Smaller: 38mm, 40mm, 41mm
• Larger: 42mm, 44mm, 45mm

Apple Watch sizes refer to the vertical case height which has increased over the years, but the width has maintained a similar enough size to not break band compatibility yet.

Where are the space gray and silver colors?

Apple Watch Series 7 has refreshed case colors for all aluminum models:

• midnight (replaces space gray)
• starlight (replaces silver)
• green (first-time color)
• blue (lighter than last year)
• red (deeper color than last year)

It’s also important to note that Apple is emphasizing that faster charging is unlocked on Series 7 only when using the “fast-charging USB-C cable” that ships with the new Apple Watch.

Our understanding is that Series 7 will not see these faster charging times when powered by Apple’s MagSafe Duo charger or other multi-charging docks. Actual testing when Series 7 is available will be required to present firm numbers.