Lexmark
40X6857
is compatible in the following Printer Models:
Lexmark Paper Handling
C950, X95x Booklet Finisher (3-Hole) (7558-FNB)
C950, X95x Booklet Finisher (4-Hole) (7558-FNB)
C950, X95x 3500-Sheet Finisher (3-Hole) (7558-FNS)
C950, X95x 3500-Sheet Finisher (4-Hole) (7558-FNS)