User`s guide

2. The legal cassette includes a rear cover to keep out foreign
material such as dirt and dust. Insert this cover into the same
holes from which the back flap was removed. You may leave
this cover permanently installed. It is compatible with the other
cassettes (fig. 4.10).
Fig. 4.10 Install Legal Cassette Dust Cover
Chapter 4
Using Optional Accessories 4-13