Juniper JSA5800 Hardware Manual page 36

5. Align the chassis inner rails with the ball-bearing shuttle, as shown in
Figure 12: Aligning the Chassis Rails with the Ball-Bearing Shuttle
6. With even pressure on both sides, slide the chassis inner rails into the middle rails until the locking
tab of the inner rail clicks into the front of the middle rail, locking the chassis into the fully extended
position.
7. Depress the locking tabs on both sides simultaneously, and slide the chassis into the rear of the rack.
Figure 12 on page 30.
30