Lexmark Forms Card 40X8603 is compatible in the following Printer Models:

Lexmark Mono Laser

Lexmark MS510dn (4514-630)
Lexmark MS610dn (4514-635)
Lexmark MS610dtn (4514-635)
Lexmark M3150dn (4514-638)
Lexmark M1145 (4514-639)