These printers use the C3909A cartridge:
HP 8000
HP LaserJet 5 SI
HP LaserJet 5 SI MOPIER
HP LaserJet 5 SI MX
HP LaserJet 5 SI NX
HP LaserJet 8000
HP LaserJet 8000 MFP
HP LaserJet 8000 DN
HP LaserJet 8000 N
HP LaserJet 8000 Series
HP Mopier 240
HP Mopier 240 Network MFP
HP Mopier 320 Network MFP
Burroughs-Unisys UDS 9624
Canon LBP 930
Canon LBP 930 EX
Canon LBP 930 EXN
Canon LBP 2460
Canon LBP WX
Canon LBP X
Canon P 550
Canon Series 5 SI
Canon Series 5 SIMX
Dataproducts DDS 24
Dataproducts DDS 24 T
Dataproducts Digital Document Server 24
DEC LN 24
Digital-DEC LN 24
Hitachi Beamstar M-324
Hitachi PC PL-2600
IBM 4324-001
IBM 4324-003
IBM 4324 Network Printer
IBM 4324 PS
IBM Network Printer 24
IBM NP 24 Network PTR 24
IBM Optra N model 240
IBM Optra N model 245
IBM UP 24 PS
Interface-Systems 9324
Interface-Systems 9624
Konica Print System 2425
Konica-Minolta Print System 2425
Lexmark 4040
Lexmark Optra N-240
Lexmark Optra N-245
Lexmark Optra N model 240
Lexmark Optra N model 245
Lexmark Optra N Pro
Lexmark Optra N Series
Mopier 8000
OCE 6535
QMS PrintSystem 2425
Source-Technologies ST 4024
TROY-Systems 624