Ricoh H545 Operator's Manual page 164

Installation
B Hold the cassette horizontally and shake it gently from side to side a
few times
C Remove the black paper and tape.
C
Hold the cassette as shown and rest it in the machine. Make sure it fits in
the slots provided on either side.
8
Note
The slots are marked with small arrows.
148
TSTT070N
TSTT060N
TSTT080N