Afro-regular is quite a LARGE cap. It is 11.4 inches (29cm) when flat and it is suitable for long braids and dreadlocks /locs reaching halfway at the back and longer depending on the volume.
Please note : Afro-regular is too big for anything less than long braids or dreadlocks. If you switch between extensions (e.g braids, etc) it is advisable to purchase different sizes for the different hairstyles.
Below : A video of Afro-Regular size in use