HP J2415A Installation And Reference Manual page 25

3. Place the hub in the rack and lower it so the notches in the bottom of the
bracket slide onto the screws. Tighten these screws—be careful not to
overtighten.
Upper hole in the bracket
Lower notch in the bracket
4. Install the other two number 12-24 screws into the upper hole in each
bracket. Tighten these screws—be careful not to overtighten.
Install additional screw
Installing the HP AdvanceStack Hub
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