Apple have released a great accessory design guide that shares the technical drawings of all of their products. If you ever wondered what the size of a particular; element was I’m sure you will find it in this guide.

These guidelines address:

• The physical design of cases, covers, screen overlays, and camera attachments for iOS and iPadOS
  devices.
• The specifications for hardware accessories using USB-C to interface with iOS and iPadOS devices.
•  The specifications for hardware accessories using the Bluetooth transport to communicate with
  iOS devices, iPadOS devices, watchOS devices, tvOS devices, and Mac computers.
•  The design of AC power adapters and battery packs for iOS devices, iPadOS devices, and AirPods.
•  The design of Qi wireless transmitters for iOS devices and AirPods.
• The physical design of band accessories compatible with Apple Watch.