imagistics DL850 Operating Manual page 316

6.
Align the hollow part of the toner cartridge with the d d d d mark on the
toner box.
7.
Push the toner cartridge lock lever backward until it stops.
8.
Return the toner box to its original position, then close the copier
front door securely.
12-4
DETAILS
Be sure to set the hollow part of the toner cartridge upward, otherwise the
machine trouble may occur.
Adding Toner (continued)