The range of door loops from CDVI offer a safe and secure method of transferring cables from a fixed point (door frame) onto the door leaf. 
The range varies from the economical “Flex” through to the CDL concealed unit. All models have a metal loop for better protection, and all have a minimum internal diameter of 7mm which is sufficient to handle the most common cables used in door locking/control. 
The GFI (CDL) is a concealed door loop - mounted in the hinge line of the door, it is completely hidden when the door is in the closed position.