This adapter has been designed to give you a flat surface where you can attach a 3M adhesive adapter plate (normally supplied with most actions cameras).
On the base there is a 25mm female, allowing you to mount to any of the Ultimateaddons 25mm male attachments / adapters. The size of this is approx 42 x 52mm.
This allows a wide range of action cameras to be
Ultimateaddons action camera plates are all made on a 1" / 25mm female Adapter plate with 3 options on how to mount your favourite action camera.