Allied Telesis AT-SBx81CFC960 - Manual (Page 137)

SwitchBlade x8112 Chassis Switch and AT-SBx81CFC960 Card Installation Guide
Section II: Installing the Chassis 137
Figure 76. Seating an Ethernet Line Card on the Backplane Connector
7. Finger tighten the two thumbscrews on the sides of the line card to
secure it to the chassis, as shown in Figure 77.
Figure 77. Tightening the Thumb Screws on an Ethernet Line Card