3D Printed - Scott Foil - Garmin Seat Post Mount
 
The mount is compatible with lots of different giant mount, they are all listed here. 
 
Garmin RVR 315 & RTL 515
 
The mount simply uses a qauter turn mount.
 
Garmin RTC 715
 
The mount locks into place with two sprung loaded buttons at opposite angles for a secure and stable hold.
 
The mount requires the insert to be changed which is very simple, undo the bolt remove the original insert and replace with the new one.
 
The RTC 715 lanyard is discounted when purchased with any RCT715 Mount