This subrack is typically used in Optical Fibre Termination Frames, with 2 x 12 fibre Incoming Ribbon Fibres.

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 internal 12 fibre optical fibre ribbon is fusion spliced to a 12 fibre ribbon/ to 12 x A/SC pigtails (housed in a break – out unit). The pigtails connect to patch cords at the patch panel. Typically the patch cords connect to transmission equipment.

A major feature of this subrack is the minimum amount of movement that occurs to transport 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 and pigtails 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.