Cisco GS7000 Installation And Operation Manual page 221

Important:

Make sure that the fiber tray fits into the two guide slots in the fiber track
near the power supplies.

Make sure that the fingers and locking tabs on the other end of the fiber tray
are inserted between the fiber track and the aluminum node housing.
5 Push down on the fiber tray housing until the fiber tray snaps into place and is
fully inserted into the node as shown in the following illustration.
Expanded Fiber Tray Installation
201