This subrack is typically used in Optical Fibre Termination Frames.
The main functions of the subrack are to provide: a managed standard fibre installation, reticulation, interconnection, distribution, re-arrangement and maintenance activities at a common point. It also allows for fibre testing and fault finding activities. Typically an external optical fibre cable is fusion spliced to pigtails, which are connected to patch cords. Typically the patch cords can cross-connect (in a FTF) or connect to transmission equipment.
A major feature of this tray is the minimum amount of movement that occurs to loose tubes and optical fibre cords, as the tray opens and closes. This ensures a very high degree of protection for working services. Also, the fusion splices are located in a protected position, because there is very little chance of them being disturbed when patch cords are being installed, as the subracks tray only needs to be opened a very small amount.