3Com 3CWE820A Quick Start Manual page 5

4 Remove the small combs from the end cap. The combs are
generally not needed, but when cut to an appropriate size they
prevent the PC Card from vibrating out of the socket when the
ECB is in an environment with extreme vibrations.
5 Gently insert the PC Card (face up) into the slot as shown in the
following figure.
6 Replace the cap, which you removed in step 2, by snapping the
cap straight down on the body.
Ethernet Client Bridge
3